-GASTEROPODA. 220 
Fossil, 86 species. Hocene—. Chili, France. 
The queen-conch (C. madagascariensis) and other large 
species are used in the manufacture of shell cameos, p. 38. The 
periodic mouths (varices) which are very prominent, are not 
absorbed internally as the animal grows. 
OnIscrIA, Sowerby. 
Hiymology, oniscus, a wood-louse. 
Synonym, Morum, Bolten. 
Type, O. oniscus; O. cancellata. Pl. VI., Fig. 15. 
Shell with a short spire and a long narrow aperture, slightly 
truncated in front; outer lip thickened, denticulated ; inner lip 
granulated. 
Distribution, 9 species. West Indies, China, Gallapagos, 
United States. (20 fathoms). 
Fossil, 3 species. Miocene. United States, Domingo. 
CASSIDARIA, Lam. 
Litymology, cassida, a helmet. 
Synonyms, Morio, Montfort. Sconsia, Gray. 
Type, C. echinophora. Pl. VI., Fig. 138. 
Shell ventricose ; canal produced, rather bent. No operculum. 
Distribution, 6 species. Mediterranean. 
Fossil, 10 species. Hocene—. Britain, France, &e. 
BACHYBATHRON, Gaskoin. 
Shell small, oblong, striated with lines of growth; spire 
small, depressed, with channelled suture; aperture with callous 
denticulated lips, like Cyprea. 
Distribution, 3 species. 
Fig. 86. Dolum perdiz. (Original). 
Dozium, Lam. The Tun. 
Type, D. galea. Pl. VI., Fig. 12. 
Shell yentricose, spirally furrowed; spire small; aperture 
very large; outer lip crenated. No operculum. Teeth 8, 1, 3. 
Fig. 86. The genus Macgillivrayia, formerly assigned to the 
Atlantidé, belongs here. It comprises the larva forms of several 
species of Dolium. 
L3 
