258 



POPULAR CONCHOLOGY 



process under the bosses ; the animal generally constructs 

 a shelly tube in which it is enclosed. Only known in 

 temperate and warm climates. 



Gastrocelena. Spengler. (Chgena, Retzius.) — Shell 

 wedge-shaped, equivalve, inequilateral, gaping very 



widely on the anterior side, united by a ligament, and 

 having no teeth, but in the interior a small spoon-shaped 

 process ; the tube is calcareous, free or fixed, and bottle- 

 shaped. Animal wedge-shaped, or elongated when the 

 siphons are extended; these are separated only at their 

 extremities, orifices fringed ; mantle closed and thickened 

 where exposed ; with a very small opening for the small 

 pointed, curved, and finger-shaped foot, which sometimes 

 spins a delicate byssus ; mouth with two equal simple lips, 

 and a pair of sickle-shaped labial tentacula.* — 3 species, 

 also fossil. 



The GastrochcBna penetrates and makes its abode in 

 hard substances ; it seldom exceeds half an inch in length, 

 and inhabits the coast of Great Britain, the Isle of France, 

 and America. Mr. Sowerby relates that he has an 

 oyster-shell in which about a dozen of these little animals 

 have taken up their abode, the shelly tubes projecting 

 more or less beyond the surface, but generally where they 

 are protected by the irregularities of the oyster-shell, f 



* Forbes 1 s British Moll. 



f Genera of Shells. 



