238 



POPULAR CONCHOLOGY. 



cular, strongly wrinkled ; the upper only half as broad as 

 the under one: lip tentacles transversely striated, the inner 

 one three times as broad as the outer one. — 8 species ; also 

 fossil. 



Philippi remarks that these shells are not easily dis- 

 tinguished from that division of Yenus called Tapes or 

 Pullastra, so that English conchologists generally class 

 them together, but the animal differs, from the foot being 

 small and bearing a byssus. It may be known from 

 Petricola by its siphons being connected nearly to their 

 points, and by its widely cleft mantle. 



R. (Yenerupis) irus and perforans are known in the 

 European seas; others are found in the Mediterranean 

 sea ; they are often lodged in holes in rocks. 



Clotho. Faujas St. Fond. — Shell oval, nearly re- 

 gular, longitudinally striated, equivalve, sub-equilateral; 

 hinge consisting of a bifid tooth curved like a crochet, 

 larger in one valve than the other.* Animal unknown. — 

 1 species fossil. 



C. Faujasii is a fossil. 



Family 3. —ANA TINA CEA. 



The animals of this family have the mantle almost entirely 

 closed, the front having only a narrow aperture for the small 

 foot ; two, generally long, thin breathing-tubes. The shell 

 is thin, often iridescent ; behind, somewhat gaping, often 

 rather inequivalve ; the ligament internal, sometimes pro- 

 vided with a moveable shelly piece. Found in the sea 

 in all climates. 



* Sow., Conch. Manual. 



