368 



SHELLS AND SHELL-FISH. 



Pandora Lam. Inequivalve, thin^ rostrated^ perlaceous ; 



one valve flat, the other convex ; ligament internal ; 



umbones small; cardinal teeth ~, lamellar, sagittate, or 



like aV reversed: connectedto^?2a^ma.(^(/. 117.5'j^.) 



P. rostrata. En. Meth. 251. f. 1. 



Mactra Linn. Equivalve ; the valves slightly gaping 

 on one side ; ligament internal and external ; cardi- 

 nal teeth complicated. 



Lutraria Lam. Shell thin, transversely oval or oblongs- 

 cardinal teeth 1^, angular, followed by a spoon-shaped 

 lobe containing the cartilage; lateral teeth none. 

 (^^.118.6.) 

 L. compressa. En. M. 257. f. 4. papyracea. Sow. Gen. f. 2. 



Mactra Linn.* Transversely oval or sub-trigonal ; um- 

 bones prominent ; cardinal teeth ^, angular, some- 



times v^ith additional laminae ; cartilage entirely in- 

 ternal, nearly central; lateral teeth i. {fig. 118. c.) 

 Neapolitana. Poll. Test, stultorum. En. M. 265. f. 2. 

 pi. 18. f. 1—5. turgida. Sow. Gen. f. 2. 



Schizodesma Gray. General character of Mactra ; but 



* Including Mactra bicolor. Sec, Auct. 



