Laganidae

Agassiz, 1873,p.516

Genre type : Laganum Link, 1807

Description succinte de la famille : Piliers internes partitionnant le test sur son pourtour externe. Périprocte infère, situé entre les premières et les secondes plaques post basicoronales paires. Présence de sillons nourriciers.

 

Sous-famille Laganinae  Agassiz, 1873

description succinte : Laganidae avec structure d'assules simples sur les ambulacres. Plaques basicoronales en forme d'étoile, les plaques ambulacraires étant plus longues.

 
 

 

 

 

Genre Laganum  Link,1807

Beschreibung der Naturalien-Sammlung der Universität zu Rostock, p.161

Espèce type  Laganum petaloides Link,1807 (par monotypie)

ibid.

Extension stratigraphique (bibliographique, non vérifiée) : Pliocène - Actuel

Syn.

  • Lagana Gray,1825, p.427

 
 
diagnose originale du genre par Link, 1807

Beschreibung der Naturalien-Sammlung der Universität zu Rostock, p.161

 
   
description du genre sensu Cotteau

Paléontologie française, Terrains tertiaires, tome 2, p.251

 

Genre LAGANUM, Klein, 1734.

Laganum, Klein, 1734 ; Gray, 1825, 1856 ; Agassiz, 1841 ; Agassiz et Desor, 1847 ; Herklots, 1854; Desor, 1857 ; A. Agassiz, 1873; Loven, 1874 ; Pomel, 4883 ; Duncan, 1890.

     Test de taille moyenne, subcirculaire, un peu allongé, plus ou moins pentagonal, déprimé en dessus, souvent renflé sur les bords, plan en dessous, subconcave aux approches du péristome. Aires ambulacraires pétaloïdes, allongées, effilées, presque fermées à l'extrémité. Zones porifères relativement étroites, formées de pores inégaux. A la face inférieure, sillons ambulacraires simples, tou­jours distincts. Tubercules petits, homogènes, épars, espacés sur la face supérieure, plus serrés vers l'ambitus et dans la région inframarginale, un peu plus gros et plus écartés aux approches du péristome. Granulation intermédiaire fine, quelquefois un peu inégale. Péristome pentagonal, subcentral, un peu rejeté en avant. Périprocte arrondi, petit, inférieur, plus ou moins éloigné du bord.

 

Appareil apical muni de cinq pores ocellaires s'ouvrant sur le bord de la plaque madréporiforme. Cinq petites plaques ocellaires. Intérieur du test dépourvu de cloisons, présentant seulement quelques piliers rapprochés de l'ambitus.

     Rapports et différences. - Le genre Laganum, établi par Klein dès 1734, a été adopté par presque tous les auteurs. En 1857, Desor en a démembré les Sismondia qui en diffèrent essentiellement par leurs aires ambulacraires ouvertes à leur extrémité, par leur appareil apical muni seulement de quatre pores génitaux et par leur cavité interne pourvue de fortes cloisons.

     Le genre Laganum, tel qu'il est aujourd'hui circonscrit, renferme quelques espèces tertiaires et un assez grand nombre d'espèces vivantes. Nous ne connaissons dans le terrain éocène de la France qu'une seule espèce, L. Sorigneti.

 

 
description du genre par Duncan, 1889

A revision of the Echinoidea from the Australian Tertiaries, p.156

 

                    Genus Laganum.

Genus LAGANUM, Klein, 1734, Nat. Disp. Ech. edit. Paris, 1754, p. 92. Gray, 1825 (Lagana), Ann. Phil. n. s. vol. x. p. 427. Agassiz, 1841,  Monogr. d'Ech. viv. et foss. livr. 2, Les Scutelles, p. 105. Gray, 1856, Cat. Rec. Ech. Brit. Mus. p. 8. A. Agassiz, 1873, Revision, p. 516. Lovén, Études, 1874, pp. 47, 83. J. Bell, 1883, Ann. Mag. Nat. Hist. vol. xi. ser. 5, p. 130. Duncan, 1885, Journ. Linn. Soc., Zool. vol. xix. p. 206, pl. 31. (Amended.)

     Syn. Rumpltia, Desor, 1858; Polyaster, Michelin; Michelinia, Duj. ; Peronella, A. Agassiz.

     Test moderate in size and large; subpentagonal or ovoid at the swollen or thin margin, truncated posteriorly, longer ibn broad, very depressed dorsally, flat or slightly concave activally.

     Apical system small, more or less stellate ; madreporite central, with or without a curved furrow, into which enter a few water­pores ; genital pores four or five, upon the flanks of the madre­porite.

     Ambulaera much larger than the interradia, but with the petaloid parts rather narrow, moderately long, nearly closed distally, plates simple ; poriferous zones with minute simple porcs in a transverse row between the cousecutive large pairs ; interporiferous areas with very numerous transverse rows of pores for minute tentacles ; actinally and at the peristome is a short groove, straight and perforate ; buccal pores large. A single spheridium, covered, in each ambulacrum.

 

     Interradia narrow ; abactinally the highest plate is single, and actinally the plates are continuons, and the peristomial plate is single.

     Peristome small, central, polygonal, formed by ten ambulacral and five interradial plates. Jaws well developed, with the teeth superior and more or less inclined. 'Perignathic processes single ; interradial, short, bent, placed beyond the limits of the pyramids.

     Periproct small, inframarginal.

     Pillars and partitions only in concentric parallel series near the edge, within the test. Tubercles and surrounding miliaries scattered, similar, usually largest actinally. Spi nes short, dorsally cylindrical, slightly swollen, larger, longer, and cylindrical acti­nally, many around the neristome and periproct. Large slender tridactyle pedicellarire near the petaloid parts of the ambulacra ; others with expanded tops on projecting stalks very general.

     Fossil. Tertiary : Europe, Asia, Java, N.'Africa (Egypt), N. America.

     Recent. East Indian Islands, Philippines, Pacifie Islands, Japan, Persian Gulf, Red Sea, Mauritius, Zanzibar, Australia, Tasmania, New Zealand.

 

 
 

Laganum laganum (Leske,1778)

 
 
diagnose originale de l'espèce par Leske,1778

Additamenta ad iacobi theodori Klein naturalem dispositionem echindermatum, p.140

 

     Ad §. 84. et 86. Species VIII. Echinodisfcus Laganum. Tab. XXII. a. b. c.

     Coniungo has duas Kleinianas fpecies. Nam icones commemoratae nullas effentiales differentias offerunt, atque a pluribus Auctoribus pro vna fpecie habentus, praeterea Cl. van phelsvm figuram minorem T. XXII. c. Kleinianam ad rvmphii Zeereal refert, a quo feparat kleinivs : vnde, fi vel nonnullae adfint differentiae, eas dubias et incertas effe apparet.     Differt autem E. Laganum a prioribus fpeciebus.

      Tefta integra, non perforata, ambulacris petaloideis fubtiliffime ftriatis, vertice prominentiori, ano circulari, margini vicino.

     Color teftae eft albo flauefcens, peripheria ouata fubpentagona. Os obtufe pentagonum, anus vix lineae latitudine a margine diftat. In bafi quinque radii excausti, ex ore ftellae inftar extenduntur, bafinque in quique fere aequales areas diuidunt. Pars harum arcarum media aliquantum eft excauata. In vertice prominentiore faepe foucola imprefla eft, atque quinque formina ibi, inter ambulacra, patent.   Ambulacra funt oualia, apice fiffa ; pori ambulacrorum fobtilissima tantum ftria, nudis oculis non cognofcenda, cohaerent. Granula totam teftam obtegentia fimilia funt reliquarum fpecierum eminentiolis.

     In ominibus fere, quae vidi, mufeis conferuatur.

     linnevs hanc fpeciem non commemorat.

     An aldrov. muf. metall. p. 457. figurae vltimae hanc fpeciem fiftant, decernere non aufim : quamuis aliquo modo fimiles videantur.

     bocc. obf. p.296. vtrum figura fecunda dorfum huius fpeciei defcribat, an ad Echinodifcum orbicularem (p.208.) referenda fit, dubito : interim margo finuofus et ambulacra porofa, eam huic fpeciei adiungendam effe, probant.

 

     rvmph. amb. T. XIV. fig. E. p 36. Zeereal. Ambitus eius magis eft rotundus, quam Kleinianae icones, interim finuofus ; diametro palmae latitudinem aequat, marginibus tenuis, in media parte calami craffitiem habet, colore albefcente, vel dilute cinereo eft. In ambulacris ftriae transuerfae, poros connectentes cuidentius apparent, quam in noftra fpecie. Caeterum eorum figura, oris anique fitus et figura cum noftra conueniunt. Etfi itaque aliquo modo a noftra fpecie recedat, tamen hae diuerfitates non tantae funt, vt diuerfam fpeciem indicent.

     gvalt. teft. Tab. CX. fig. C. C. Echinodifcus fubrotundus, margine integro, finuofo, fubalbidus. gvaltiervs commemorat bonan. Claff. I. no. 33. fed in mea editione Claff. I. 20. numeros tantum habet, neque vllibi haec fpecies indicatur.

     sebae thef. III. Tab. XV. fig. 25. 26. Echiniplani fcutiformis fpecies altera. Icones bonae.

     plot. n. b. of Oxfordsh. p. 92. §.33. f. 12. Petrefactam hanc fpeciem haud dubie indicat. In vertice funt quatuor impreffa puncta, eftque infloar rogae foliorum diuifus : fubftantia eius lutefcens, non tamen lamellofa, neque annulis inftructa eft. plotivs radios ex duplici ordine transverfarium linearum compofitos, exterioresque longiores effe et ad marginem lapidis extendi perhibet, quod tamen in figura non apparet.

     In mufeo Trieriano duo fpecimina petrefacti huius Echinodifci bene conferuata, reperiuntur.

 

 
 

Laganum laganum (Leske,1778) - Pliocène, Tainan, Taiwan, 39 mm

 
 
     
 

 

 

 

Genre Cenofibula  Gasser,1994

Un nouveau Clypeasteroide de l'Eocene catalan, p.13-16

Espèce type  Cenofibula castriauliensis Gasser,1994 (désignation originale)

ibid.

Extension stratigraphique (bibliographique, non vérifiée) : Bartonien

 
 
 

Cenofibula castriauliensis Gasser,1994

 
 
 

Cenofibula castriauliensis Gasser,1994 - Eocène moyen, Igualada, Barcelone, Espagne, 11 mm

 
 
     
 
 

Cenofibula castriauliensis Gasser,1994 - Eocène moyen, Igualada, Barcelone, Espagne, 16 mm

 
 
 

 

 

Genre Jacksonaster  Lambert & Thiery,1914

Essai de nomenclature raisonnée des échinides, p.313

Espèce type  Laganum depressum Agassiz,1841 (désignation subséquente de Lambert & Thiery,1914, Essai de nomenclature raisonnées des échinides, p.313)

Monographies d'échinodermes, des Scutelles, p.110

Extension stratigraphique (bibliographique, non vérifiée) : Miocène - Actuel

 

 
 
 

Jacksonaster depressum Agassiz,1841, Pléistocène, Egypte, 53 mm

 
 
   
 
 

Jacksonaster depressum Agassiz,1841, Pléistocène, Jordanie, 46 mm

 
 
 
 

Jacksonaster depressum Agassiz,1841, Plio - Pléistocène, Egypte, 23 et 16 mm

 
 
   
 

 

 

 

Genre Peronella  Gray,1855

Catalogue of the recent echinida of sea eggs in the collection of the British Museum, p.13

Espèce type  Laganum peronii Agassiz,1841 (désignation originale)

Extension stratigraphique (bibliographique, non vérifiée) : Pléistocène - Actuel

Syn.

  • Lambertiella Checchia Rispoli, 1917, p.57 ; espèce type : Lambertiella pulchra Checchia Rispoli, 1917

 
 
 

Peronella archerensis (Twichell,1915)

 
 

diagnose originale de l'espèce par Twichell,1915

The Mesozoic and Cenozoic Echinodermata of the United States, p.161

 

Laganum archerensis Twichell, n. sp.
Plate LXXV, figures 1a-d.

    Determinative characters.—Test small, subpentagonal to subdecagonal in marginal °titane. General form subdiscoidal, upper surface very low, nearly parallel with lover surface, with a slightly concave ring involving most of ambulacral petals between the faintly tumid apical region and the notably thickened margin. Highest part of test along anterior margin. Lower surface flat. Ambulacral petals subelliptical, extending two-thirds the way to the margin, ends closed. Apical system_ slightly excentric anteriorly, with four genital porcs set unusually far apart. Peristome small, pentagonal, central; ambulacral grooves simple, straight lines flanked by finely granulated areas, the five constituting a peristomial star. Periproct small, transversely suboval, about one-fourth the way from margin to peristome.

     Dimensions.—Length 18 millimeters ; width 16 millimeters; height 3.5 millimeters.

     Description.—Only a single specimen of this new Laganum lias been discovered. It was found at Archer, Fla., whence the name here given. The test is small, subpentagonal or sub­decagonal iu marginal outline. The whole form is greatly depressed; subdiscoidal, the upper surface being practically parallel with the lower; the apical region faintly tumid, the area between the apical region and the margin slightly concave; the margin notably thick-ened, slightly less so posteriorly than anteriorly. The lower surface is flat. The highest part of the test is along the surface of the anterior margin, from whence the upper surface slopes gently to the posterior margin, the central tumidity being hardly any higher than the sicle margins.

     The ambulacral petals are subelliptical, extending about two-thirds the way to the margin, the larger part of each petal being depressed so as to form a part of the concave ring on the upper surface, the ends of the petals practically closed. The poriferous zones are rather wide, about half as wide as the interporiferous areas, the proximal ends poorly defined, the inner row of pores round, the outer row slitlike, the pairs of pores conjugated.

     The interambulacral areas are very narrow, especially at the margin, where they are hardly more than one-third as avide as the ambulacral areas. The whole surface of the test, including the interporiferous areas and apical region, is covered with small tubercles set in deep scrobicules, which are larger on the under surface.

 

      The apical system is slightly excentric anteriorly at the summit of the faintly tumid central area. There are four large genital pores, set unusually far apart, the anterior pair being neetrer together than the posterior pair. The poriferous zones could not be seen to corne together at the proximal ends, and the perforations in the radial plates coulcl not be discerned on the specimen.   

The peristome is small, central, pentagonal. The ambulacral grooves each consist of a central impressed hne and two narrow areas of fine granulation which are bounded by faint lines; these grooves are quite distinct for a short distance from the peristome, thus constituting a well-defined peristomial star, they then become gradually less distinct, so that as the margin is approached they can hardly be discerned.

      The periproct is small, about half the diarneter of the peristome, transversely suboval, about one-fourth the way from the margin to the peristome.

     Related forms.—L. archerensis is most closely related to L. dalli, but can be easily dis­tinguished by the concave ring on its upper surface, by its narrower petals, its less depressed and narrower poriferous zones, and by having its periproct doser to the margin. It is also allied to L. floridanum, but lias a less regularly oval marginal outliue and a larger petaloidal area. It (Mers from L. crustuloides in being lower centrally, in having a concave ring on its upper surface, and in having n flat lower surface.

     Locality.—Archer, Fla.

     Geologic horizon.—Vicksburg group, lower Oligocene.

     Collection.—U. S. National Museum (164667a).

planche LXXV (extrait)

   

 

 
 

Peronella archerensis (Twichell,1915) - Eocène Moodys Branch Formation, Yankeetown, Floride, U.S.A., 20 mm

 
 
     
 
 

Peronella lesueuri (Agassiz,1841)

 
 

diagnose originale de l'espèce par Agassiz,1841

Monographies d'échinodermes, Echinites, Famille des Clypéastroides, seconde monographie, des Scutelles, p.116

 

VIII. Laganum lesueuri Val.

Tab. 24, fig. 3-6.

     C'est la plus grande espèce du genre ; elle atteint jusqu'à 5 1/2 pouces de longueur sur 5 pouces de large. La hauteur est peu considérable, elle n'atteint pas même 1. pouce dans les plus grands exemplaires. Le bord n'est point renflé comme dans les espèces du type du Lag . Bonani, et par la même raison il n'existe point de dépression entre ce dernier et le sommet. Le pourtour du test est polygonal, et l'on remarque une espèce de troncature en face de chaque ambulacre ; ensorte que si l'on voulait préciser rigoureusement les contours du test, on trouverait qu'il est décagonal. Ces troncatures ambulacraires sont toujours plus petites que la partie qui correspond aux aires interambulacraires. Au rebours des espèces précédentes, le côté antérieur est sensiblement plus large que le côté postérieur. Les pétales ambulacraires se font remarquer par leur étroitesse, comparée à la grandeur du test ; ils sont tout d'une venue, et, au lieu de s'arrondir, ils sont comme tronqués à leur extrémité. L'espace intermédiaire entre les zones porifères est plus large que ces zones elles—mêmes. Les pores oviducaux sont très apparens , mais au nombre de quatre seulement , situés à l'extrémité des rayons du corps madréporiforme , qui affecte la forme d'une étoile à cinq rayons très prononcés et échancrés à leur extrémité (voyez dans la fig. 6 , la rosette apiciale grossie). Il m'a été impossible d'apercevoir les trous ocellaires ; cependant je ne doute pas qu'ils n'existent dans les sinus du corps madréporiforme , au sommet des ambulacres. La face inférieure est complètement plane. L'ouverture buccale est centrale et circulaire ; sur son pourtour se voient les tubes branchiaux qui ont à leur extrémité plusieurs ouvertures plus ou moins distinctes (voyez fig. 5 , qui représente la bouche grossie). La rosette buccale n'est pas bien distincte ; quant aux sillons ambulacraires, ils sont très marqués près du centre et criblés d'une quantité de pores microscopiques , mais ils disparaissent vers le bord. Les aires interambulacraires sont excessivement étroites à la face inférieure, où elles se présentent sous la forme de bandes indistinctement limitées ; c'est dans une de ces bandes que s'ouvre l'anus , qui est très rapproché du bord. Sa forme est circulaire , mais il semble percé obliquement de dehors en dedans. Une granulation très uniforme recouvre toute la surface du test. Les tubercules spinifères , un peu plus gros à la face ,inférieure qu'à la face supérieure , naissent du milieu d'une dépression très prononcée, et l'espace intermédiaire est garni d'une quantité de tubercules miliaires. Les soies, même celles qui s'articulent aux

 

tubercules spinifères, sont très grêles; mais examinées à la loupe , elles se montrent distinctement carénées (fig. 3 b), et si l'on vient à les observer sous un plus fort grossissement, on trouve que ces carènes sont hérissées de petites dentelures très acérées (fig. 3 c).

     La cavité intérieure n'a ni cloisons ni piliers, et le réseau de cellules n'existe que sur les bords, où il est cependant plus varié que dans le Lag. Bonani. La rosette apiciale interne affecte la forme d'une étoile composée de cinq rayons, qui s'étendent dans les aires interambulacraires et à l'extrémité desquelles s'ouvrent les pores génitaux. La carène qui correspond à l'aire interambulacraire ne diffère des autres qu'en ce qu'elle est un peu plus forte et qu'elle n'a point de pore génital; au reste sa forme et sa structure sont les mêmes.

     Cette espèce a été rapportée par Péron et Lesueur de leur voyage aux terres australes et par M. Plée de la Guadeloupe. Je n'en connais pas d'autres exemplaires que ceux du Muséum de Paris. C'est M. Valenciennes qui le premier a reconnu les caractères spécifiques qui la distinguent du Laganum tonganense.

     Ainsi que je l'ai dit plus haut, lorsqu'on aura une connaissance plus approfondie de ses rapports anatomiques , cette espèce devra probablement former le type d'un genre à part , auquel se rapporteront également les Laganum elongatum et rostratum et peut–être aussi le L. tonganense.

planche 24 (extrait)

   

 

 
 

Peronella lesueuri (Agassiz,1841), Pléistocène supérieur, Mid-West district, région de Leeman, Western australia, 117 mm

 
 
 
 

Peronella lesueuri (Agassiz,1841), Pléistocène supérieur, Mid-West district, région de Leeman, Western australia, 87 mm

 
 
 

 

Genre Rumphia  Desor,1858

synopsis des échinides fossiles, p.229

Espèce type  Laganum rostratum Agassiz,1841 (désignation originale)

Extension stratigraphique (bibliographique, non vérifiée) : Miocène - Actuel

Syn.

  • Polyaster Michelin, 1859, non Gray, 1840

  • Peronellites Hayasaka & Morishita, 1947, p.101 ; espèce type : Peronellites ovalis Hayasaka & Morishita,1947

 
 
 

Rumphia orbicularis (Leske,1778) - Pléistocène supérieur, Bilbra formation, Outback district, Western Australia, 20 mm

 
 
 
 
 

Rumphia orbicularis (Leske,1778) - Pléistocène, Dampier Limestone, Western Australia, 20 mm

 
 
 
 
 

Rumphia ova (Mc Namara,1996), Pliocène supérieur, Australie de l'Ouest, 30 mm

 
 

Rumphia ricta (Gregory,1892)

 

diagnose originale de l'espèce par Gregory, 1892

Further additions to Australian fossil Echinoidea, p.433

Species, Laganum decagonale, Lesson. Var. rictum, n. var. Pl. XII. Fig. 1.

   

     Diagnosis (of the Variety).

     Form : elongated elliptic ; the posterior end is longer and narrower than the anterior ; the anterior end is semicircular ; the sides taper backward. The base is flat ; the margins are tumid, and are separated from the slightly conical apex by either a flat platform or a slight broad depression.

     Ambulacra : Petals extend two-thirds of the distance from the apex to the ambitus ; the lateral pairs are equal in length ; the anterior ambulacrum is the longest. The petals are sharply closed below ; the width of the pore area expands rather gradually to the distal end of the petal, then is there closed somewhat abrubtly. The interporiferous areas are large, and taper slightly to the blunt distal end.

     Apical system : at the apex of the test. The madreporite is raised, large, and central. There are four large genital pores. Of the radial (ocular) pores the right antero-lateral is very large ; those of the right postero-lateral and left antero-lateral ambulacra are small ; the left postero-lateral pore is not developed.

     Peristome : mouth somewhat pentagonal ; large ; the width is half as much again as the length. It is situated before the centre. There are no interradial actinal furrows.

     Periproct : the anus is large and almost circular ; it is close to the margin.

   

     Distribution. - Cainozoic. Shark's Bay, West Australia.

Collected by Harry Page Woodward, Esq., F.G.S.

     Affinities and Differences. - The specimen on which this species is founded is unquestionably a very close ally of Laganum decagonale, Less., though as to whether it should be regarded as a variety or a distinct species, I do not care to express an opinion on a single specimen. It differs from that

 

species by the elliptical and somewhat pentagonal shape of the mouth, and the absence of the five interradial furrows which radiate from the mouth. The British Museum contains a large series of specimens of that species, but the circular form of the mouth is constant ; the actinal depressions do vary in debree of development, but I have not seen one in which it is not quite distinct. These two characters may not improbably be of specific value.

     The shape of the test differs from the normal decagonal form ; but some specimens of the species have a form identical with the fossil.

     Herklots figured a specimen from the Java Tertiaries as Scutella decagona, n. sp., Martin referred this to Peronella decagonalis, Ag., and included L. angulosum, Herklots, as a synonym ; but as Herklots neither figured nor described the actinal side, a certain amount of doubt must remain as to the accuracy of this determination. As the present variety differs from the previously known species in the same points as L. decagonalis, it need not be compared more closely with them.

planche XII (extrait)

   

 

 

Rumphia ricta (Gregory,1892), Pléistocène moyen - Shark Bay district, Australie occidentale, 65 mm

 
 

Rumphia ricta (Gregory,1892) - Lutétien supérieur, Gironde, 27 mm

 

Genre Sismondia  Desor,1857

synopsis des échinides fossiles, p.225

Espèce type  Scutella occitana Defrance,1827 (désignation subséquente de Pomel (1883) Classification méthodique et genera des echinides vivants et fossiles, p.72)

Extension stratigraphique (bibliographique, non vérifiée) : Eocène moyen - Miocène inférieur

Syn.

  • Sismondaea Meyer-Eymar, 1897, p.2 ; nomen vanum

 
 

Sismondia occitana (Defrance,1827), Lutétien supérieur, Gironde, 27 mm

 
   
 

Sismondia archiaci Cotteau,1883, Lutétien , Charente Maritime, 23 mm

 
 

 
 
 

Sismondia intermedia Fabre, Lutétien , Médoc, 13 mm

 
 
   
 
 

Sismondia testudo Cotteau,1891, Bartonien, Calcaire de Blaye, Médoc, 8 & 10 mm

 
 
   
 

 
 

Sous-famille Neolaganinae  Durham,1954

description succinte : Laganidae avec structure d'assules pseudo-composée sur les ambulacres. Plaques basicoronales arrangées pentagonalement.

 
 
 

Genre Cubanaster  Sanchez Roig,1952

El genero Cubanaster (Equinidos fosiles irregulares). p.3

Espèce type  Jacksonaster torrei Lambert in Sanchez Roig, 1926 par monotypie

Extension stratigraphique (bibliographique, non vérifiée) : Eocène moyen - fini Eocène

 
 
 

Cubanaster torrei Lambert in Sanchez Roig, 1926

 
 
 

Cubanaster torrei Lambert in Sanchez Roig, 1926 - Eocène supérieur, Chiapas, Mexique, 36 mm

 
 
 
 

Cubanaster torrei Lambert in Sanchez Roig, 1926 - Eocène supérieur, N Tuxtla gutierres, Chiapas, Mexique, 41 mm

 
 
 
 

Cubanaster torrei Lambert in Sanchez Roig, 1926 - Eocène supérieur, Chiapas, Mexique, 39 mm

 
 
 
 

Genre Wythella  Durham,1954

Classification of clypeasteroid echinoids, p.682

Espèce type  Laganum eldridgei Twitchell,1915 (désignation originale)

Extension stratigraphique (bibliographique, non vérifiée) : Eocène moyen - fini Oligocène

 
 
 

Whytella eldridgei Twitchell,1915

 
 

diagnose originale de l'espèce par Twitchell

Mesozoic and Cenozoic chinodermata of the United States, 1915, p.160.

 

Laganum eldridgei Twitchell, n. sp.

Plate LXXIV, figures 2a-d.

     Determinative characters. - Test large, subpentagonal to subdecagonal in marginal outline, longitudinally elongate, truncated at the anterior and posterior ends, more or less undulating along the sides. Whole form greatly depressed, margin thin bhut thicker than slightly concave submarginal area, petaloidal region tumid. Apex and apical system subcentral. Lower surface flat. Ambulacral petals long, elongate elliptical, extending two-thirds the way to the margin, pointed and closed at the ends ; pairs of pores conjugated by very narrow more or less wavy grooves. Ambulacral areas very wide at margin, narrowing rapidly to ends of petals. Peristome moderate in size, subcentral, subpentagonal to subelliptical, transversely elongate. Ambulacral grooves apparently simple and straight, each groove having a fine line on both sides which rapidly diverge from the main groove. Periproct relatively large, suboval, longitudinally elongate, one-fourth the way from the margin to the peristome.

     Dimensions. - Length 96 millimeters ; width 75 millimeters ; height 10 millimeters.

     Description. - The only specimens known of this large and handsome Laganum, the largest representative of the genus from American deposits, were collected in Florida by the late G. H. Eldridge of the United states Geological Survey and the species is therefore named in his honor. The test is large, being 3 to 4 inches long and 21/2 to 3 inches wide. In marginal outline it is subpentagonal to decagonal, decidedly longer than broad ; margin thin but thicker than the submarginal area, truncated at anterior and posterior ends, more or less undulating along the sides. The whole form is greatly depressed, the upper surface slightly concave around the submarginal area, arising centrally in the form of a low mound which involves the whole petaloidal area ; apex subcentral ; lower surface flat.

     The ambulacral areas are very wide at the margin, being there about four times the width of the interambulacral areas, narrowing rapidly to near the ends of the petals. The petals are long, elliptical in outline, extending two-thirds the way to the margin, pointed and closed at the ends. The anterior pair shorter than the other three, which are subequal in length. The poriferous zones are wide, more than half the width of the rather narrow interporiferous areas, inner row of pores elliptical, outer row very narrowly slitlike, hardly discernible, pairs of pores conjugated by very narrow more or less wavy grooves.

     The interambulacral areas are very narrow at the margin, widen rather rapidly to near the ends of the petals, and narrow again toward the apical region. The whole test is closely set with very small tubercles, among which are scattered at irregular distances some larger ones in deep scrobicules.

     The apical system is subcentral, at the summit of the tumid area. There are four large genital pores, of which the anterior pair are set closer together than the posterior pair. No other details could be made out on the specimens.

     The peristome is of moderate size, subcentral, slightly to the rear of the apical system, subpentagonal to subelliptical, transversely elongate. The details of the ambulacral grooves could not be mad out satisfactorily on the specimens studied. As they leave the peristome there appears to be a single straight groove on each side of which are two fine lines which rapidly diverge from the main groove. These side lines may be the boundary lines of what on better preserved specimens would prove to be finely granulated areas, thus forming a peristomial star.

     The periproct is relatively large, about half the size of the peristome, suboval, longitudinally elongate, situated about one-fourth the way from the margin to the peristome.

     Related forms. - L. eldridgei is readily distinguished from all other American forms. It closely resembles L. elongatum Agassiz, whose origin is unknown and which is not even stated to be fossil, being very similar in size, general form, and marginal outline, but differs from it in having a suboval instead of circular periproct, placed a little farther from the posterior margin.

     Locality. - Suwanee River, Fla.

     Geologic horizon. - Vicksburg group, lower Oligocene.

     Collection. - U.S. National Museum (164683).

Extrait planche LXXIV

   
 
 

Whytella eldridgei Twitchell,1915, Eocène supérieur, Mills Mine, Hernando County, Floride, U.S.A., 32 mm

 
 
 
 

Whytella eldridgei Twitchell,1915, Eocène supérieur, Floride, 42 mm

 
 
 

 
 

Genre Weisbordella  Durham,1954

Classification of clypeasteroid echinoids, p.682

Espèce type  Peronella caribbeana Weisbord,1934 (désignation originale)

Extension stratigraphique (bibliographique, non vérifiée) : Eocène supérieur

 
 
 

Weisbordella cubae (Weisbord)

 
 
 

Weisbordella cubae (Weisbord), Eocène supérieur, Crystal river, Citrus County, Floride, 32 mm

 
 
 
 

Weisbordella cubae (Weisbord), Eocène supérieur, Hernanco county, Floride, 43 mm

 
 
 
 

Weisbordella johnsoni (Twitchell,1915)

 
 

diagnose originale de l'espèce par Twitchell

Mesozoic and Cenozoic chinodermata of the United States, 1915, p.162.

 

Laganum johnsoni Twitchell, n. sp.

Plate LXXV, figures 2a—d.

     Description and deterininative characters.—The test of this new Laganum is modorate in size and almost regularly oval in marginal outline. The upper surface is moderatcly elevated centrally, the height being about one-third of the width, the tumid area extending to the ends of the petals; the submarginal area about equal in thickness to the margin, which is slightly undulating, very thick, high and rounded, thicker and higher than in related forms, slightly thinner at the middle of the posterior end thon elsewhere. The lower surface is decidedly concave, the coucavity reaching nehrly to the margin and near the peristome being about equal to one-half the height of the test. The apex is subcentral. The posterior petals are lanceolate, the anterior three subelliptical, all of thern pointed and closed at the ends, extending two-thirds or more of the way to the margin, the anterior pair slightly shorter than the rest. The poriferous zones are very narrow, much narrower than the slightly tumid interporiferous areas, sometimes irregular, inner ends poorly defined, inner row of pores round, outer row slitlike, pairs of pores conjugated. The whole surface. of the test is covered with rather conspicuous small tubercles which are linger on the lower surface. The apical system is sub­central, with four large genital pores. The peristome is small, subpentagonal, subcentral; ambulacral grooves poorly defined, not well preserved on the specimen. The periproct is small, subcircular to subpentagonal, about one-third the way from the margin to the peristome.

     Dimensions.—Length 34 millimeters; width 30 millimeters; height 10 millimeters.

     Related forms.—This species is very closely related to L. crustuloides, in fact so close that further collecting may lead to its being made a synonym of the latter species. Its chief distinguishing features are its greater height and tue greater height and thickness of its margin. These features distinguish it not only from L. crustuloides, but aise from the other American representatives of the genus, from which it differs also in its pronouncedly concave lower surface.

     Locality.—Turks Cave, Ala.

     Geologic horizon.—Probably Vicksburg formation, lower Oligoeene.

     Collection.—U. S. National Museum (137202); collected by L. C. Johnson, after whom it is named.

Extrait planche LXXV

   
 
     
 
 

Weisbordella mirabilis (Jackson,1922)

 
 

diagnose originale de l'espèce par Jackson,1922

Fossil echini of the west Indies, p.47

 

Peronella mirabilis, new species.
(Plate 9, Figure 3.)

     The following is a description of this species:

     Test small, thin, elongate, subpentagonal in outline, dorsally slightly elevated, with rounded low margin, flat ventrally. Ambulacral petals are narrow, pointed, but open slightly at the tips. Petals I, V, and III are of the same length, 6 mm.; petals II and IV are a little shorter, 5 mm. in length. Poriferous areas are narrow and curved; interporiferous areas lanceolate, about half as wide again as a poriferous area. Apical disk anterior, 8 mm. from the anterior border and 9.5 mm. from the posterior border of the test. Peristome and periproct are invisible, as they are covered up by matrix on the ventral side. The most remarkable feature of this species is the tubercles; dorsally there are 6 large, perforate primary tubercles, sunken in deep pits, the upper part of the tubercles being flush with the surface of the test; 2 of these large sunken tubercules are situated in interambulacrum 1 and there are also 2 in interambulacrum 4. In the anterior interambulacra 2 and 3 there is in each area one of these large tubercles, a most distinctive and, as far as I know, unique character in the Clypeastroida.1 Secondary tubercles of medium size are scattered over the test dorsally; ventrally they are similar, but more closely associated. There are 4 genital pores, the pore being absent in area 5, as is typical in the genus. Several madreporic pores exist.

     There are 2 specimens of this new species. The larger measures 3 mm. in height, 18 mm. in length, and 17 mm. in width. The fact that there are only 4 genital pores indicates that this species should be referred to the genus Peronella.

     This species is remarkable in the large primary tubercles which occur on the dorsal side. The only clypeastroid apparently to which it can be compared is the Recent Clypeaster lampas H. L. Clark (C. latissimus A. Agassiz, Blake Echini, plate 15c), in which species there are a number of large tubercles on the ventral side; but they are not sunken in pits and are quite numerous instead of very limited in number. A better comparison structurally of the peculiar large tubercles in Peronella mirabilis is to compare them with similar tubercles seen in

 

the spatangoids Lovenia and the Recent Maretia tuberculata A. Agassiz and Clark (1917, Mem. Mus. Comp. Zool., vol. 46, No. 2, plate 160, figs. 5 to 7). In this comparison with spatangoids the similar character is a pure case of parallelism.

     The second specimen, which is somewhat srnaller and less perfect than the holotype, is instructive in that it shows a similar distribution of the large primary tubercles, 2 in interambulacrum 4 and 1 in inter­ambulacrum 3. They also doubtless existed similarly in interambulacra 1 and 2, but these areas are worn away. This species was associated in the same lot with Echinolampas ovumserpentis, as collected by J. A. Bullbrook.

     Eocene, San Fernando formation, Vitabella Road, Mount Moriah, San Fernando, Trinidad, J. A. Bullbrook collector; 2 specimens, U. S. Geol. Sur. station 8878; the holotype, U. S. Nat. Mus. No. 328247; and a paratype, U. S. Nat. Mus. No. 328248.

planche 9 (extrait)

   

 

 
 

Weisbordella johnsoni (Twitchell,1915) - Eocène supérieur, chiapas, Mexique, 39 mm