Dr. J. E. Gray on sorne Families of Bivalve Shells. 41 1 



B. Siphons separate, elongate, slender. 



8. 7>//imW.p,Syn. B.M. 1842, 75; P. Z. 8.1847, 186. Pedal 

 opening elongate. Shell oblong, cartilage internal or external. 



2. Cardinal teeth diverging, central laminar, folded ; cartilage 



internal, in a triangular pit. 



9. Mactrada, Syn. B. M, 1842, 75; P. Z. S. 1847, 185; Ann. 

 and Mag. N. H. 1853, 38. 



10. Paphiada, P. Z. S. 1847, 186 ; Ann. and Mag. N. H. 

 1853, 38. Mesodesmidse, St/n. B. M. 1842, 75. Mantle lobes 

 united. Pedal opening small, anterior. Gills truncated behind. 

 Siphons shoi-t, separate, anal largest. 



11. ?Anatellid<£, Ann. and Mag. N. H. 1853, 38. Animal 

 unknown. 



3. Cardinal teeth very oblique, hinder nearly parallel ivith hinge- 



margin ; cartilage external, marginal ; umbones subspiral. 



12. Glossida, P. Z. S. 1847, 195. Isocardiadje, Syn. B. M. 

 1842, 80, Foot compressed, truncated, short, small; pedal 

 opening rather contracted ; lips simple ; shell free. 



13. Chamada, Syn. B. M. 1842, 79; P. Z. S. 1847, 193. Foot 

 very small, rather produced in front; lips foliated; pedal opening 

 very small ; shell irregular, attached by the outer surface of one 

 valve. 



Fig. 1. 



Animal of Chama from Torres' Straits. 

 a, a, adductor muscles ; p, pedal muscle ; d, dental membrane ; t, labial 

 tentacle ; ff, small outer gill ; e, anal siphon ; b, branchial siphon ;/, pedal 

 orifice ; m, palUal line ; o, portion of left mantle lobe occupied by ovarium ; 

 /, liver. — S. P. Woodward. 



4. Hinge tooothless ; cartilage internal, in a pit, with a shelly 

 appendage in front. 



14. Anatinida, Syn. B. M. 1842, 77; P. Z. S. 1847, 190. 

 Siphons elongate, generally separate. Gills pinnate, apparently 



