from the Island of Malta. 77 



rather nearer the anterior than the posterior border. The disc 

 consists of a central madreporiform spongy body, around which 

 the genital and ocular plates are arranged in a circle; their 

 sutural lines of union, however, are concealed, and can only be 

 seen in weathered specimens. The base is convex ; the mouth 

 is very large, and lies in a deep depression opposite the vertex ; 

 it is surrounded with five oral lobes of small size, with inter- 

 vening petaloidal depressions, perforated with holes in pairs. 

 The interambuiacrum is slightly produced posteriorly. The 

 anus is a large transversely oblong opening, situated near the 

 margin. The border of the test is rather obtuse. The tubercles 

 are of uniform size on the dorsum, and are larger and less 

 numerous than in E. Kleinii. 



Affinities and differences. This species resembles much E. 

 scutiformis, but is distinguished from it by the greater narrowness 

 of the ambulacral areas, and the absence of the transverse slits 

 or sulci by which the pairs of pores in these avenues are in 

 general united. The tubercles are more abundant on the dorsal 

 surface in E. Deshayesii, and the dorsal surface is not so much 

 elevated in that species as it is in E. scutiformis. 



Locality and stratigraphical range. This species was col- 

 lected from bed No. 2, the yellow sand, at Malta. Desor gives 

 the " Tert. moyen. d'Oran (Algerie) et de Carthagene (Cata- 

 logue) " as his localities ; and we have received from M. Michelin 

 of Paris a specimen from the Miocene terrain of Balistro, Cor- 

 sica, which has enabled us to identify the Maltese Urchin, and 

 make out the preceding description, the first given of this pretty 

 form. 



Echinolampas Richardi, Desmarest. 



SYN. Scutum ovatum Issyaviense, Klein, Echinodermatum, tab. 20. 



fig. a, 4, 77. p.29(?). 

 Clypeaster Richardi y Desm. Diet. Sc. Nat. t. liv. tab. 5. p. 12, spec. 



ined. in litt. ; Grateloup, Mem. Echin. Foss. tab. 1. fig. 8 a, b, 



p. 44. 

 Echinolampas Richardi t Desmoulins, Etudes sur les Echinides, p. 34 2. 



no. 4. 

 Echinolampas Laurillardi t Agassiz and Desor, Ann. Sc. Nat. t. vii. 



p. 165. Scilla, Corp. Mar. tab. 1 1, top figure, showing the base 



only. 



Test oblong, produced posteriorly, rounded before, flattened 

 laterally, caudate posteriorly ; dorsal surface convex, elevated ; 

 base concave ; mouth central ; anus inframarginal, lodged in 

 a caudal process of the interambuiacrum ; ambulacral areas 

 narrow, with contracted poriferous zones. 

 Dimensions. Antero-posterior diameter 1^ inch, transverse 



diameter l ff % inch, height ths of an inch. 



