212 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



Subgenus Rangianella, Conrad, 1868. Type. — Macira mendica, Gould. 

 Section Miorangia, Dull. M. Johnmni, Dall. 



Subfamily PTEROPSIDIN^. 



(jrenus PxEROPsrs, Conrad, 1860. Eocene. 

 Type. — Lutraria papyria, Conr. 



Genus Labiosa (Schmidt), Mollcr, 1832. 

 Type. — Mactra anaiina, Spengler. 



Subgenus Raeta^ Gray, 1853. Type. — Lutraria canaUculata, Say. 



Section liaetina, Dall. li. indica, Dall, n.s. 



Subgenus Haetella, Dall. Type. — E. tenuis (Hinds MS.), Dall. 



Subfamily LTJTRARIIN^. 



Genus Lutraria, Lam., 1799. 

 Type. — L. ohionya, Gmel., sp. 



Section Lutraria, s.s. L. ohionya, Gmelin. 

 Section Goniomactra, C. Mayer. L. impar, Desh. 

 Section Lutropliora, Dall. L. complanata, Gmel. 



Genus Tkesijs, Gray, 1853. 

 Type. — T. Nuttallii, Conr. {Schizothcerus). 



Genus Standella, Gray, 1853. 

 Type. — Mactra fray His, Gray, non Chemnitz =Jf. pellucida (Ch.), 

 Gmelin {non Standella, H. & A. Ads.). 



Subgenus Eastonia, Gray, 1853. Type. — Mactra rugosa, Gmelin. 



Genus Heterocardia, Deshaycs, 1854. 

 Type. — II. gibhosula (Desh.), Adams. 



Subfamily ZENATIIN^. 



Genus Zenatia, Gray, 1853. 



Type. — Z. acinaces, Quoy and Gaim., sp. 



Genus Eesania, Gray, 1853. 

 Type. — R. lanceolata, Gray. 



Genus Darina, Gray, 1853. 

 Type. — L. solenoides. King, sp., non Lam. 



