CONCHYLIA— D/THFiiJ. xix. 



23. Mactra. — Denies laterales transversim laminosi, valvee 

 alterius didymi. 

 The lateral teeth transverse and laminar, those of 

 one valve double. 

 21. Lepton. — Denies laterales valvce alterius transversim 

 bipartiti. 

 The lateral teeth of one valve deeply cloven 

 transversely. 



40. NucuLA. — Denies primaru cochleariformes, lateralibus 

 numerosis. 

 The primary teeth spoon-shaped, with numerous 

 lateral ones. 



19. Kellia. — Valva altera [dentibus duobus approximatis, altera 

 dente erecto concavo. 

 In one valve two teeth close together, and a single 

 erect concave tooth in the other. 

 24. GooDALLiA. — Valva altera dente unico, altera dentibus duobus 

 cum fovea trigond interpositd. 

 In one valve a single tooth, in the other two teeth 

 with a triangular cavity between them. 



'B2 



