PELECYPODA. 



39 



Solens were considered a dainty dish by the ancient Greeks, and 

 numbers are still eaten by the poorer coast-population of this 

 country and abroad. 



The Myida, popularly known as "Gapers," on account of their Casi 

 valves being- open at one or both ends, have the mantle united all -° F ^ 

 round, except where the small foot is protruded. The siphons are 



Fio\ 28. 



British Gaper {Mya truncata). 



a, foot ; b, siphon-sheath ; c, exhalaut siphon ; d, inhalant siphon ; 

 e, umbones or beaks ; f, anterior, g, posterior end of shell. 



very long-, united almost to the ends, and covered with a coarse 

 wrinkled outer skin. They bury themselves in mud and sand at 

 low-water mark or in shallow water. The species are few in 

 number, and chiefly from the shores of northern countries. Mya 

 armaria of our own coasts is largely eaten in some parts of 

 Europe and North America. 



The family Corbulida contains a large number of mostly small 

 shells, varying much in shape and sculpture. The true Corbuke 

 have one valve larger than the other and are like little Mya, but 

 the valves are almost closed and their siphons are very short. 



The Lucinida are almost invariably white shells, and may 

 generally be recognized by the very long muscular scar in front 

 on the inner surface of the valves. They occur in all parts of 

 the world ; and the fossil forms, which are still more numerous 

 than those now living, have existed at every epoch from the 

 Silurian. 



The Astartida have strong solid shells, frequently ornamented 



Case 



•20 g.1 



[Cases 

 l'Oii-i'Ia. 



[Case 21, 



A-B.] 



