PHE GASTROPODA 165 
short, obtuse posteriorly ; shell thick with a short spire, the last whorl 
large and the canal short ; aperture wide ; columella flattened ; operculum 
horny. Genera—Purpura, Bruguiére; shell not umbilicated, aperture 
smooth ; British. Rapana, Schumacher ; shell ventricose, umbilicated. 
Monoceros, Lamarck ; shell like that of Purpura, but the aperture shifted 
backward and bearing a conical tooth on its external border. Sistrwm, 
Montfort ; shell thick, spiny, the aperture contracted by the thickening 
of the margins of the aperture. Concholepas, Lamarck ; shell ovoid, the 
spire short and the aperture widely dilated. Faminy 8, Hatiipag, 
Fischer. Foot large and thick ; without an operculum ; tentacles thick 
and flattened ; shell ventricose, thin, and smooth, with a wide aperture. 
Genus—Halia, Risso; from Cadiz and Morocco, Faminy 9. CANCEL- 
LARIIDAE, Adams. Snout short; tentacles long, with the eyes at their 
bases and external; foot small; no operculum; siphon short; shell 
ovoid with short spire and folded columella. Genus — Caneellaria, 
Lamarck. Famity 10. CoLtumBEeLLtipAr, Adams. Foot large, tentacles 
long and convergent; spire of shell prominent, aperture narrow, the 
canal very short and the columella crenelated, 
Genus — Columbella, Lamarck. Faminy 11. 
CORALLIOPHILIDAE, Chenu. Foot short ; ten- 
tacles slender and convergent ; siphon short ; 
radula absent; shell irregular; sedentary 
animals living in corals. Genera— Corallio- 
phila, Adams; shell deformed, with a wide 
aperture and a short canal ; operculum present. 
Rhizochilus, Steenstrup; no operculum; the 
aperture of the shell irregular, with the canal 
prolonged into a tube. Leptoconchus, Riippel ; 
no operculum ; the shell globular with a wide 
aperture. Magilus, Montfort ; an operculum 
present ; the last whorl of the shell uncoiled 
and very thick. Rapa, Klein; an operculum 
present ; shell globular and umbilicated, the 
aperture provided with a canal. Faminy 12. 
VoLuTiIpar, Gray. Head very flattened, and 
transversally widened, with the eyes on the Conus lineatus, ventral aspect. 
sides 5 snout short ; foot broad ; siphon with Tore Pecan 
internal appendages. Genera— Voluta, Lin- cavity; U1, operculum; LV, an- 
naeus; head with eyes; Australian seas. ue pee rateae VE 
Guivillea, Watson ; no eyes; abyssal. Cymba, siphon; VII, mouth. (After 
Broderip and Sowerby ; viviparous. FamIny aa 
13. Onivipak, d’Orbigny. Eyes, when present, on the middle of the 
tentacles; fore part of the foot with a transverse groove; a posterior 
pallial tentacle ; generally burrowing. Genera— Oliva, Bruguicre ; eyes ; 
no operculum. Olivella, Swainson; tentacles without eyes ; an operculum. 
Ancillaria, Lamarck. <Agaronia, Gray. Famity 14. MARGINELLIDAE, 
Adams. Foot very large; mantle reflected over the shell. Genera— 
Marginella, Lamarck ; foot without operculum; a central gland-pore. 
Pseudomarginellu, Carriere ; foot with an operculum and an anterior gland- 
