The Echinoid Directory

• Test of moderate size, subovate in outline, inflated, with a relatively flat adoral surface, slightly sunken towards the peristome.
• Apical disc subcentral; monobasal, with four gonopores.
• Petals well developed; bowed and open distally. Pore-pairs small, subconjugate; the inner pores round, the outer pores elongated transversely. The two columns of pore-pairs in each petal highly asymmetric, being of very unequal lengths; the inner column of the posterior paired petals being between half andf two-thirds the length of the outer column.
• Peristome subcentral, elliptical, transverse, wider than long.
• Periproct inframarginal and transverse; not sunken.
• Phyllodes simple, only slightly developed, single pored, with a single series, plus scattered pores in between.
• Bourrelets feeble, confined to a distinct well leading to the peristome opening.
• Buccal pores present.
• Narrow, naked, granular zone in interambulacrum 5.

Miocene to Recent, worldwide distribution.

Echinolampas depressa Gray, 1851, p. 36; by subsequent designation of Lambert, 1918, p. 44.

• E. (M.) depressa (Gray, 1851); Recent, Florida, Venezuela
• E. (M.) manzonii (Pomel, 1883); Helvetian, Miocene, Malta
• E. (M.) eurysomus (Agassiz, 1839); Lutetian, Switzerland
• E. (M.) circularis (Sanchez Roig, 1953); Recent, Cuba
• E. (M.) keiensis (Mortensen, 1948); Recent, Kei Islands, Indonesia
• E. (M.) mattseeensis (Quenstedt, 1875); Lutetian, Austria
• E. (M.) koreana Clark, 1925; Recent; Korea, Japan
• E. (M.) sternopetala Agassiz & Clark, 1907; Recent, Japan

Irregularia; Cassiduloida;Echinolampadidae

Pomel (1883) erected this genus and differentiated it by its lack of bourrelets and weak phyllodes. These are juvenile characters and are likely to show greater development in larger specimens. He included three species, depressa, manzonii and eurysomus

Miolampas has the very marked inequality in the length of the two series of pore-pairs in each petal, the shorter pore-series measuring between half to two-thirds of the length of the longer pore-series; one of the characteristic defining features of Mortensen\'s Echinolampas (Planilampas).

It would appear that there has been a transposition of images between Kier\'s (1962) plate 30, fig. 1 and plate 31, fig. 2. The apical view of E. oviformis (ovatus) (plate 30, fig. 1) does not closely match the oral view; the apical view showing a more rounded posterior margin, the oral view with a more angular posterior margin typical of E. ovatus. This oral view more closely matches the supposed apical view of E. depressa (plate 31, fig. 2). This is most likely a mistake, and would explain why Kier\'s figure of E. ovatus has such asymmetrical petals (typical of E. depressa), while the figure of E. depressa has less asymmetrical petals more typical of E. ovatus.

Lambert & Thiery (1909-1925) use the type species of Miolampas for describing their section (subgenus) five of Echinolampas; to which they refer 76 species.

P. M. Kier. 1962. Revision of the cassiduloid echinoids. Smithsonian Miscellaneous Collections, 144 (3) 262 pp.

J. Lambert & P. Thiery. 1909-1925. Essai de nomenclature raisonnee des echinides. Libraire Septime Ferriere, Chaumont, 607 pp., 15 pls.

Pomel, A. 1883. Classification méthodique et genera des Échinides vivante et fossiles. Thèses présentées a la Faculté des Sciences de Paris pour obtenir le Grade de Docteur ès Sciences Naturelles, 503, 131 pp. Aldolphe Jourdan, Alger.