226 MANUAL OF THE MOLLrSCA. 



Distrihution, 14 species. Mediterranean, Ceylon, China, Aus- 

 tralia, Pacific. 



Fossil, 7 species. (? Chalk. Britain). Tertiary. South Europo. 



Sub-genus, Malea, Yalenc. (D. personatum), outer lip 



thickened and denticulated ; inner lip with callous prominences. 



Haepa, Lam. Harp-shell. 



Type, H. ventricosa. PI. VI., Fig. 11. (= Buc. harpa, L.) 



Shell Yentricose, with numerous ribs, at regular 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. Eocene—. Erance. 



COLTTMBELLA, Lam. 



Etymology, diminutive of columba, a dove. 



Type, C. mercatoria. PI. VL, Eig. 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, Gallapagoa, California. Small, prettily- 



• D. perdix, L. species. | natural size (after QuojO- Vanicoro, Pacific. The 

 I roboBciff is exserted, and the siphon recurved over the front of the shell. 



