116 MANUAL OF THE MOLLUSCA. 



Fossil, 7 sp. (? Chalk. Brit.) Miocene — . S. Eiu^ope. 

 Suh-yenus, malea, Yalenc. (D. personatum) outer lip thickened and denti- 

 culated ; inner Mp with callous prominences. 



Hakpa, Lam. Harp-shell. 



Type, H. ventricosa. PL VI., fig. 11. (=Buc. harpa, L.) 



Shell, ventricosa; with numerous ribs, at regular intervals; spii'e small; 

 apertm-e large, notched in front. No operc. 



The animal has a very large foot, with the front crescent-shaped, and 

 divided by deep lateral fissm-es from the posterior part, which is said to sepa- 

 rate spontaneously when the animal is irritated. Mostly obtained fr'om deep- 

 water, and soft bottoms. 



Distr., 9 sp. Mauritius, Ceylon, Philippines, Pacific. 



Fossil, 4 sp. Eocene — . Prance. 



COLOIBELLA, Lam. 



Etym., diminutive oi columba, a dove. 



Type, C. mercatoria. PL VI., fig. 10. 



Shell, smaU ; with a long narrow aperture ; outer lip thickened (especi- 

 ally in the middle), dentated ; inner lip crenulated. Operculum very small, 

 lamellai'. 



Distr., 200 sp. Sub-tropical. W. Indies, Medit., India, Gallapagos, 

 California. Small, prettily-marked shells ; living in shallow water, on sandy 

 flats, or congregating about stones. (Adams.) 



Fossil, 8 sp. Miocene — . (The Brit. sp. are pisa7:ia) . 



Suh-genus. Columbellina, D'Orb. 4 sp. Cretaceous. Prance, India. 



Oliva, Lam. Olive, rice-shell. 



Type, 0. porphyria. PL VI., fig. 16. Syti., strephona. Brown. 



Shell, cylindrical, polished ; spire very short, sutm-e channelled ; aper- 

 ture long, narrow, notched in front ; columella callous, striated obliquely ; 

 body whirl fui-rowed near the base. No operc. in the typical sp. 



Animal, with a very large foot, in which tlie shell is half immersed ; 

 mantle lobes large, meeting over the back of the shell, and giving off filaments 

 which lie in the suture and fruTow. The eyes are placed near the tips of the 

 tentacles. 



The oHves are veiy active animals, and can turn over, when laid on their 

 back ; near low water they may be seen gliding about or bm-ying in the sands 

 as the tide retires ; they may be taken with animal baits, attached to lines. 

 They range downwards to 25 fms. 



Distr., 117 sp. Sub-tropical, W. and E. America. W. Africa, India, 

 China, Pacific. 



Fossil, 20 sp. Eocene — . Brit., Prance, &c. 



