from the Island of Malta. 73 



areas are more equally lanceolate at the base and apex, the 

 inner row of pores of the same curve more gracefully outwards, 

 and the anus is further from the border in S. Brongniartii than 

 in S. subrotunda. The size and pyriform shape of the ambu- 

 lacral areas, the absence of sinuosities in the margin, and the 

 greater convexity of the dorsal surface, distinguish S. Paulensis 

 from S. subrotunda. 



Stratigraphical range and distribution. This species is not un- 

 common in the calcareous sandstone bed No. 4, and in the junc- 

 tion beds of No. 5, the hard cherty limestone, at Malta. It is 

 found likewise " in the marine calcaire grossier in the environs of 

 Bordeaux ; at Bazas, Leognan, Gradignan, Douai, in Dauphine ; 

 in Tourraine; in Anjou; at Montpellier." (Grateloup.) 



History. The table of synonyms shows the phasis of the 

 history of this species, although other forms have been mistaken 

 for it : in fact, the species of Scutella approach each other so 

 closely, that, without an authentic series of specimens for com- 

 parison, similar mistakes may be made. This Urchin is found 

 in all the public collections. The specimens before us are from 

 Malta and Leognan. 



Scutella striatula y Marcel de Serres. 



SYN. Scutella striatula, Marcel de Serres, Geognosie des Terrains 

 Tertiaires, p. 156 ; Desmoulins, Etudes des Echinides, no. 25. 

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

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



Scutella subrotundtty 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 2j 7 ^ inches, trans- 

 verse diameter 2 T 9 ^ inches, height /^ths of an inch. 



Desnnption. This Urchin so nearly resembles S. subrotunda, 

 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 specimens 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 S. striatula may be distinct 

 from S. subrotunda. The ambulacral rosette is small ; the areas 

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

 diameter of the test ; the apical disc is small ; the madreporitnriM 



o2 



