VOL. XI, PP. 89-92 APRIL 26, 1897 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



SYNOPSIS OF THE AMERICAN SESARM.E, WITH 

 DESCRIPTION OF A NEW SPECIES. 1 



BY MARY J. RATHBUN. 



The American species of Sesarma are in much confusion, owing 

 partly to incomplete descriptions and to the study of isolated 

 specimens. The following is a key to all the species known to 

 occur in America, with their principal synonyms, based on a 

 study of types. One new species is described from the Museum 

 at Copenhagen by permission of Dr. F. Meinert. 



Sesarma Say. 

 SYNOPSIS OF AMERICAN SPECIES. 



A. Carapace with a tooth behind the outer orbital tooth. 

 B. Maims with two or more pectinated ridges on the upper surface. 



Subgenus Perisesarma de Man. qfricana** Milne Edwards. 



W. Manns without pectinated ridges on the upper surface. 



Subgenus Sesarma = Episesarma de Man. 

 C. Front less than half the greatest width of the carapace. 



bidentata* Benedict. 



C x . Front more than half the greatest width of the carapace. 

 D. Upper surface smooth. 

 E. Eyes reaching the outer angle of the orbit. 



curacaoensis de Man. 

 E'. Eyes not reaching the outer angle of the orbit. 



reticulata* Say. 



1 Published with the permission of the Secretary of the Smithsonian 

 Institution. 



2 Occurs at Barbados. 



3 Type species of the genus. 

 *Type examined by the writer. 



20 BIOL. Soc. WASH., VOL. XI, 1897 (89) 



