120 Dr. T. Wright on Fossil Echinoderms 



p. 234 ; Agassiz, Monogr. cles Scutelles, tab. 18. fig. 1-5. p. 81 ; 



Agassizand Desor's Cat. raison., Ann. Sc. Nat. tom.vii. p. 134. 



Scutella suhrotunda, Grateloup, Mem. Ours. Foss. tab. 1 . fig. 1. p. 36. 



Test very flat^ suborbicular; dorsal surface very slightly convex ; 

 ambulacral areas small, short and narrow, less than the semi- 

 diameter of the disc ; base nearly flat; mouth central; anus 

 marginal ; ambulacral sulci bifid. 



Dimensions. — Antero-posterior diameter 2^'^ inches, trans- 

 verse diameter 2-^q inches, height /(jths of an inch. 



Description. — This Urchin so nearly resembles *S^. suhrotunda, 

 that it may be doubted whether it is entitled to rank as a distinct 

 species, or ought rather to be considered as a variety of that 

 form. The two s])eciraens before us are from localities widely apart 

 from each other. One is from the Miocene terrains of Terre- 

 Negre, near Bordeaux, the other from the calcareous sandstone 

 of Malta. Still the similarity exhibited by these specimens, and 

 the persistence of those characters which have been considered 

 as specific, incline us to think that 8. striatula may be distinct 

 from >S'. suhrotunda. The ambulacral rosette is small ; the areas 

 are short, narrow and lanceolate, and are less than the semi- 

 dianietcr of the test ; the apical disc is small ; the madreporiform 

 tubercle is prominent and central ; the granulations are almost 

 microscopic; the base is flat ; the mouth is small and central, 

 and the anus marginal ; the ambulaci'al sulci are bifid ; the 

 margin of the test is thin, and the sinuosities well marked. Let 

 the studv'ut compare these characters with the detailed description 

 of S. suhrotunda given in the preceding article. 



Locality and straiigraphical range. — It was collected from bed 

 No. 4, the calcareous sandstone at Malta, where it is not common. 

 Our French specimen is from the middle tertiarics of Terre- 

 Negre. 



Genus Echinolampas (Gray, 1835). 



Test of an elongated or subdiscoidal form ; petaloid portion 

 of the ambulaci-al areas large, generally elevated into convex 

 leaves, contracted towards the base, where they cease to rise 

 above the level of the test ; inferior surface concave towards the 

 mouth, which is median, symmetrical, pentagonal, and sur- 

 rounded by five lobes ; basal portions of the ambulacra with five 

 short poriferous zones around the mouth ; anus transversely 

 oblong and inframarginal; apical disc small and excentral, five 

 genital and five ocular plates placed around the madreporiform 

 body ; tubercles small, uniform and numerous, sunk in the test, 

 and surrounded by ring-like areolas. Three species are living 

 in the seas of warm latitudes ; the others are fossil, mostly in 



