VOL. XVI, PP. 5-8 FEBRUARY 21, 1903 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



REVIEW OF THE CLASSIFICATION OF THE 

 CYRENACEA. 



BY WILLIAM H. DALL. 



In working over the Cyrenacea for the Memoir on the Ter 

 tiary Fossils of Florida, in course of publication by the Wagner 

 Institute of Science, it was found that both the nomenclature 

 and the classification were in a state of deplorable confusion. 

 While the details are reserved for that memoir, it was thought 

 that a synopsis of the arrangement adopted might be of use to 

 the students of the group, and it is herewith presented. 



Family Cyrenidtt. 



Genus Miodontopsia Ball (nov.). Type Cyrena media Sowerby. Juras 

 sic. This is Miodon Sandberger, 1870, not Carpenter, 1865. 



Genus Loxoptychodon Sandberger, 1872. Type Cyrena intermedia De- 

 shayes. Lower Eocene, France. 



Genus Plesiastarte Fisher, 1887. Type P. crenulata Deshayes (as 

 Cyrena). Lower Eocene, France. 



This is Anomala Cossmann, 1886, not Hubner, 1816. 



Genus Ditypodon Sandberger, 1872. Type Cyrena suessii C. Mayer. 

 Lower Pliocene of Italy. 



?Genus Donacopsis Sandberger, 1872. Type Cyrena acutangularis De- 

 S-PROC. BIOL. Soo. WASH. VOL. XVI, 1903. (6) 



