GASTEROPODA. 



87 



Harpa. Lam. — Shell oval, smooth, and marked with 

 parallel longitudinal ribs, the upper end of each, near the 



large, much wider than the shell, \ f ' '!$ 



and twice as long, pointed behind, Harpa ventrkosa ~ V 



the front part on each side divided 



by a notch, crescent-shaped, and rising above the head ; the 

 mantle on the left side prolonged, and in front formed into 

 a long breathing tube ; the head between the long ten- 

 tacula, the eyes somewhat above the base of the latter ; the 

 proboscis small; tongue unarmed. — 9 species*; also fossil. 



The principal localities of this genus are the Red Sea 

 and the Indian and South American Oceans. The Harpa 

 imperialism from the Mauritius, is a remarkably beautiful 

 shell, and exceedingly rare : at one time it could only be 

 procured at an extravagant price, but now it is more 

 common. It is distinguished by the very great number of 

 ribs, which, indeed, are almost close together; and the 

 colours and markings are very elegant and beautiful. 

 There is a fishery for them at the Mauritius and the neigh- 

 bouring islands, and they are taken at night and at sun- 

 rise, when they are probably feeding. Some naturalists f 

 affirm that the animal can, when attacked by an enemy, 

 disembarrass itself of part of its foot, and retire entirely 

 within its shell. The ribs in this genus are evidently the 

 remains of what has been the mouth of the shell at dif- 

 ferent periods. The II. ventricosa is the most common 

 species of this genus, and perhaps the most beautiful. 



sutures, is projecting and pointed; 

 spire short; last whorl large and 

 deeply notched ; outer lip thick- 

 ened : it is supposed to have no 

 operculum. Animal, foot very 



* Reeve's Iconica. 



f MM. Quoy and Gairaard, and M. Reynaud. 



G 4 



