GASTEROPODA. 267 '' 



its inner side, and slightly so externally; operculum shelly, 

 multi- spiral. 



Distrihution, 6 species. "West Indies — China. Low water to 

 (JO fathoms. 



Fossil, 5 species. Tertiary — . Britain. 



EuoMPHALUS, Sowerby. 



Etymology, eu, wide, and omphalos, umbilicus. 



Synonyms, Schizostoma, Bronn. Straparollus, D'Orbigny. 

 Ophileta, Yanuxem. Platyschisma, M'Coy. 



Type, E. pentagonalis. PI. X., Fig. 18. 



S?ieU depressed or discoidal ; whorls angular or coronated ; 

 aperture polygonal ; umbilicus very large ; operculum shelly, 

 round, multi-spiral. (Salter.) 



Fossil, 80 species, L. siluiian— Trias. North America, Europe, 

 Australia. 



Sub-genus. Plianerotinus, J. Sby. 1840, E. cristatus, Phil. 

 Carb, limestone. Britain. 



Shell discoidal ; whorls separate ; outer margin sometimes 

 foliaceous. 



Stomatella, Lam. 



Etymology, diminutive of stoma, the aperture. 



Type, S. imbric-ita. PI. X., Fig. 19. 



Shell ear-shaped, regular ; spire small ; apei'ture oblong, very 

 large and oblique, nacreous; lip thin, even-edged; operculum 

 circular, horny, multi-spiral. On reefs and under stones at 

 ow water. 



Distrihution, 33 species. Cape, India, North Australia, 

 China, Japan, Philippines. 



Suh-genus .? Oena, Gray. Spire minute, marginal ; no 

 operculum. 16 species. Eed Sea, India, Seychelles, Swan 

 Biver, Philippines. (Adams.) 



Niphonia, Adams. 1 species, Japan. 



Broderipia, Gray. 



Etymology, named in honour of W. J. Broderip, Esq., the 

 distinguished conchologist. 



Type, B. rosea. PL X., Fig. 20. 



Shell minute, limpet-shaped, with a posterior sub-marginal 

 apex ; aperture oval, as large as the shell, brilliantly nacreous. 



Distribution, 3 species. Philippines; Grimwood's Island, 

 South Seas. (Cuming.) 



n2 



