226 MANUAL OF THE MOLLUSCA. 
Distribution, 14 species. Mediterranean, Ceylon, China, Aus- 
tralia, Pacific. 
Fig. 87.# 
Fossil, 7 species. (? Chalk. Britain). Tertiary. South Hurope. 
Sub-genus, Malea, Valenc. (D. personatum), outer lip 
thickened and denticulated; inner lip with callous prominences. 
Harps, Lam. MHarp-shell. 
Type, H.ventricosa. Pl. VI., Fig. 11. (== Bue. harpa, L.) 
Shell ventricose, with numerous ribs, at reguiar intervals; 
spire small; aperture large, notched in front. No operculum. 
The animal has a very large foot, with the front crescent- 
shaped, and divided by deep lateral fissures from the posterior 
part, which is said to separate spontaneously when the animal 
is irritated. Mostly obtained from deep water and soft bottoms. 
Distribution, 12 species. Mauritius, Ceylon, Philippines. 
Pacific. 
Fossil, 4 species. Hocene—. France. 
CoLUMBELLA, Lam. 
Hiymology, diminutive of columba, a dove. 
Type, C. mercatoria. Pl. VI., Fig. 10. 
Shell small, with a long narrow aperture ; outer lip thickened 
(especially in the middle), dentated; inner lip crenulated. 
Operculum very small, lamellar. 
Distribution, 205 species. Sub-tropical. West Indies, Medi- - 
terranean, India, Gallapagos, California. Small, prettily- 
* D. perdiz, L. species. 4 natural size (after Quoy). Vanicoro, Pacific. The 
] roboscis is exserted, and the siphon recurved over the front of the shell. ‘ 
