Vol. XI, pp. 109-110 May 13, 1897 



PROCEEDINGS 



OF THR 



BIOLOGICAL SOCIETY OF WASHINGTON 



SYNOPSIS OF THE AMERICAN SPECIES OF ETHUSA, 

 WITH DESCPJPTION OF A NEW SPECIES * 



BY MARY J. RATHBUN. 



The type si)ecies of EtJiusa, E. mascarone (Herbst) of tlie 

 Mediterranean, is represented in tlie West Indian region by a 

 form so slightly different that it cannot be regarded as more 

 than a subspecies. E. mascarone americana. E. microphthabna is 

 found in the deej^er waters off the Atlantic coast of North 

 America; E. lata and E. ciliatifrons occur on the Pacific coast 

 of tropical America. To these a fifth species is now added, 

 E. ienuipes, from the Gulf of ISIexico and Florida Keys. 



Synopsis of American Species of Etlium. 



A. Eye-stalks long, extending laterally beyond the postorbital spine. 



mascarone americana A. Milne Edwards. 

 A^. Eye-stalks short, directed forward. 



B. Branchio-cardiac lines meeting in front of tlie heart. 



ciliatifrons Faxon. 

 B'. Branchio-cardiac lines not meeting in front of the heart. 



C. Dactyli of second and third pairs of legs broad, vertically com- 

 pressed. 

 D. Third joint of antennae reaching the extremity of the frontal 

 teeth. lata Rathhun =^ pubescens Faxon. 



D/ Third joint of antennae not reaching the extremity of tlie 

 frontal teetli. viicropJithalma Smith. 



C Dactyli of second and third pairs of legs slender, not vertically 

 compressed. tenuipes Rathbun, new species. 



* Published with the permission of the Secretary of the Smithsonian 

 Institution. 



25— Biol. Soc. Wash., Vol. XI, 1897 (lOLI) 



