SPII^ERIUM. 



57 



The specimens from which this description was prepared were 

 kindly furnished to me by Mr, Swift, of St. Thomas. In propor 

 tion to its size this species is quite robust. It is different from 

 the generality of the West Indian and South American Sphseria 

 by its sulcations, which are regular and deep. In shape and 

 appearance it recalls the young of S. sulcatum. It is allied to 

 S. veatleyii in outline, but otherwise it differs, being heavier 

 and of a larger size. 



Fig. 58. 



38. Sphaerium parviiliim, PRIME. Animal not observed. 

 Shell small, transversely-oblong, inequilateral, moder 

 ately compressed ; beaks calyculate, prominent ; anterior 

 side narrower, rounded ; posterior subtruncate ; striae very 

 delicate ; epidermis greenish-gray ; teeth slight, but well 

 marked. 



Long. 0.15 ; Lat. 0.11 ; Diam. 0.06 inches. 

 &quot; 3| ; &quot; 2f ; &quot; 1 mill. 



Hob. At Hamacao in the Island of Portorico, West Indies. (Cabinets 

 of Smithsonian Institution, Morelet and Prime.) 



In outline this species offers some resemblance to S. bahiense , 

 it is, however, much less inflated. 



S. parvulum. 



39. Sphaerium viridante, MORELET. Animal not observed. 



Shell small, transversely-oblong, compressed, delicate, inequilateral ; 

 anterior side somewhat narrow, shorter, rounded ; posterior 

 subabrupt, basal margin slightly rounded ; beaks inclined Fig. 59. 

 towards the anterior, very small, calyculate, approximate at 

 apex ; valves slightly compressed ; striae very regular and 

 delicate ; epidermis greenish-brown, irregularly mottled with 

 large blotches of a darker color ; hinge margin nearly 

 straight ; cardinal teeth diminutive 

 posterior tooth longer. 



Long. 0.24; Lat. 0.18 



viridante. 



lateral teeth slight, 



Diam. 0.13 inches. 

 &quot; 6; &quot; 4J; 3^ mill. 



Hab. At Pomte-a-Pitre in the Island of Guadeloupe, West Indies. 

 nets of Smithsonian Institution, Morelet and Prime.) 



(Cabi 



The specimens from which this description was prepared were 

 obtained from the author. This species is very closely allied to 

 S. meridionale ; it differs, however, in being transversely less 

 long, less produced at the posterior ; it is also less compressed. 

 Found not unplentifully. 



