448 fissurellid;e. 



neglecta, Desh. Sieboldii, Tleeve. 



nigro-ocellata, Tteeve. Singaporensis, Reeve. 



nigro-radiata, Reeve. solida, Phil. 



octagona, Reeve. suffusa, Reeve. 



Panameiisis, Sow. tegula. Reeve. 



Philippiana, Dkr. Ticaonica, Reeve. 



pica, Sow. venusta, Reeve. 



quadriradiata, Pieeve. vimiuea, Reeve. 



reticulata, Donov. viridula, Lam, 

 Riippellii, Sow. 



Genus CLYPIDELLA, Swain son. 



Mantle-margin double, the edges scalloped and fringed, 

 anal siphon surrounded by a fimbriated membrane ; foot 

 large, fleshy and tubercular, with a series of rudimentary, 

 tentacular filaments on the sides near the fore part. 



Shell ovate, scutiform, surface rugose, the anterior ex- 

 tremity slightly elevated, truncate and sub-emarginate ; 

 perforation large, situated near the fore part of the shell. 



Ea:. C. pustula, Linnaus, pi. 51, fig. 3. Shell, C. 

 pustula, fig. 3, a. 



In this genus the sides of the shell are covered by the 

 upper fold of the double-edged mantle, the anal siphon is 

 encircled by a fringed and plicate membranous expansion, 

 and the foot is fleshy and tubercular. 



Species of Clypidella. 



aculeata, Reeve. pustula, Linn. 



Baikiei, A. Adams. salebrosa, Reeve. 



dubia. Reeve. scutella, Gray. 

 fascicularis, Lam. 



