204 



EXPLANATION OF PLATE 3 

 Figure Page 



11. Barbatia domingensis (Lamarck) 37 



12. Arcopsis adanisi conradiaiia (Dall) 37 



13. Noetia ponderosa (Say) 38 



14. Glycymeris pectinata (Gmelin) 38 



Fig. a. Interior view. Fig. b. Exterior view. 



15. Atrina rig'ida (Solander) 40 



16. Atriiia serrata (Sowerby) 40 



