318 INTRODUCTION TO CONCHOLOGY. 



The genus abounds in the Nile and other rivers of Africa, 

 and is found in company with Galatht^a radiata, Cailliaud 

 observes^ that the shells are used by the natives of Lower 

 Egypt in preparing flax_, and also as spoons for measuring 

 oil and butter^ and different kinds of provisions. 



The Ihcetopi have little affinity with the Iridince : the 

 lobes of the mantle are free, aud they have no syphons ; 

 their chief peculiarity consists in a long extended cylindrical 

 foot, inflated at the extremity, and incapable of being with- 

 drawn. The shell gapes widely at both ends, and seems 

 to indicate a new organization in the animal inhabitant. 

 We may presume, therefore, that the raollusk occasionally 

 changes his abode, — that, unlike many of his brethren, 

 who moor their floating citadels to rocks or the stems of 

 giant sea-weeds, he is free to range at will. 



Family YIII. Trigonacea. 



It may be, that in days long glided by, 

 When some wild wave had cast thee on the shore, 

 Tubal pass'd by, and, stooping, with quick hand 

 Bore thee rejoicing to his palm-roofed home. 



The Trigonacea may be described as having an equivalve 

 shell, with the hinge composed of a few broad lamelliform 



