320 



littorinidj:. 



The recent species are few in number, one is from Senegal, 

 two are from the Mediterranean, and the others are from 

 the Eastern Seas, and South America. 



Sjjecies of Fossar. 



abjectus, C. B. Adams 



(Adeorbis). 

 ambiguus, Linn. 

 angiostoma, C. B. Adams. 

 bicarinatus, A. Adams. 

 clatliratus, Phil. 

 costatus, Brocc. 

 Cumingii, A. Adams. 



excavatus, C. B. Adarns. 

 foveatus, C. B. Adams. 

 megastoma, C. B. Adams. 

 pusiUus, Gould (Tricho- 



tropis). 

 reticulatus, A. Adams. 

 trochlearis, A. Adams. 

 variegatus, A. Adams. 



Genus ISAPIS, H. and A. Adams. 



Shell umbilicated ; spire elevated, whorls rounded, 

 transversely ribbed and cancellated ; aperture ovate ; 

 columella slightly arcuated, with a strong tooth in the 

 middle ; outer lip simple externally, strongly lirate inter- 

 nally, margin dentate. 



£x. I. anomala, C. B. Adams, pi. 33, fig. 8. 



This genus, of which but a single species is known, 

 is founded upon a curious little shell described by the 

 late Professor Adams as Narica anomala; the tooth in the 

 middle of the inner lip is the principal character which 

 distinguishes the genus from Fossar. 



Genus LITHOGLYPHUS, Miillfeldt. 



Tentacles subulate ; eyes at their outer bases. 



Operculum ovate, few-whorled. 



Shell semiglobose, thick, solid ; spire short, obtuse. 



