56 



CONCHIFEEA. 



Corhula (Brugiiiere) . Shell roundish, nearly 

 equal-sided, very unequal- valved ; hinge a tooth in 

 one or both valves, with socket and ligamental pit 

 beside it. Animal with very short united siphons ; 

 fringed orifices ; mantle opening for the passage of 

 a narrow thick foot ; anal siphon with a projecting 

 tubular membrane. 



C. nucleus, 

 rosea. 



Fig. 73 ; n.s. 



74 



75 



76 



Sphcenia (Turton). l^early as Corhula. Shell 

 oblong ; hinge an erect dilated tooth in one valve, 

 and a socket in the other. 



S. Binghami. Fig. 74 ; n. s. 



My a (Linn.). Gaper. Shell rhomboidal, equal- 

 valved ; hinge a spoon-shaped process in the left 

 valve, and a socket in the right. Animal with 

 united retractile siphons, and a small conical foot. 



M. truncata. Fig. 75 ; J n. s. 

 arenaria. 



Family V. Solenid^. 



Shell greatly dilated, parallel-sided, gaping at 

 both ends ; ligament external ; hinge with com- 



