GA.STEEOPODA. 265 



Distriliition, 200 species. "World-wide. Low water to 15 

 fathoms ; the smaller species range nearly to 100 fathoms. 



Fossil, 361 species. Devonian — . Europe, North America, 

 ChiH. 



Suh-genera. Pyramis, Chemn., Tr. obeliscus. PI. X., Fig. 6. 

 Columella contorted, forming a slight canal. 



Gibbula, Leach. Tr. magus, Britain. 



Shell depressed, widely umbilicated ; whorls tumid. Head- 

 lobes largely developed ; lateral cirri, 3. 



Enida, Adams. 3 species, Japan. 



Margarita, Leach. Tr. helicinus. PI. X., Fig. 7. 



Shell thin ; cirri, 5 on each side. 



Distribution, 17 species. Greenland, Britain, Falkland 

 Islands. Near low water, under stones and sea-weed. 



Elenchus, Humphrey (= Canthiridus, Montfort) E. iris. PI. 

 X., Fig. 8. Smooth, thin, imperforate, with a prominent base. 

 Australia, New Zealand. F. Iris scarcely differs in form from 

 Tr. zizyphinus ; F. hadiiis is IJie a pearly phasianella ; and 

 E. varians (bankivia, Menke) would be called a chemnitzia, if 

 fossilised. PL X., Fig. 9. 



Alcynus, Adams. 2 species, Japan» 



Minolia, Adams. 1 species, Japan. 



Turcica, Adams. 1854. 



Vitrinella, C. B. Adams, 1850. Shell minute, hyaline, 

 turbiniform, umbilicated ; aperture large, orbicular. 



Distribution, 18 species. "West Indies (5), Panama. 



Fhotinida, H. and A. Adams, 1855. Shell heliciform ; spire 

 soniewhat acute. 



EoTELLA, Lamarck. 



Etymology, diminutive of rota, a wheel. 



Synonym, Helicina, Gray. 



Type, E. vestiaria. PI. X., Fig. 10. 



Shell lenticular, polished; spire depressed; base callous; 

 lingual teeth 13; uncini numerous, sub-equal. 



Distribution, 15 species. India, Philippines, China, New 

 Zealand. 



MoNODONTA, Lam. 



Etymology, monos, one, and odous {odontos), a tooth. 

 Synonyms, Labio, Oken. Clanculus. Montfort, OKvia, Eisso. 

 Tijpes, M. labeo. PI. X., Fig. 21. M. pharaonis. PI. X., 

 Fig. 12. 



Shell turbinated, few-whorled ; whorls spirally grooved and 



