VOL. XVII, PP. 161-162 DECEMBER 27, 1904 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



DESCRIPTIONS OF THREE NEW SPECIES OF 

 AMERICAN CRABS. 



BY MARY J. RATH BUN. 



A number of crabs were lent some years ago to the U. S. Na 

 tional Museum by the Zoological Museum at Copenhagen, for 

 the author's use in a monograph of American Brachyura. As 

 the completion of this publication is indefinitely postponed , the 

 new species, the types of which are in the Museum at Copen 

 hagen, are briefly described here. 



Uca oersted! sp. nov. 



Type. Male, from a lot of 2 males, 1 female, from Punta Arenas, Costa 

 Rica ; Mr. CErsted, collector. 



Surface uneven; a deep groove on outer side of gastric and cardiac regions 

 is continued anteriorly in a transverse groove behind orbits, and posteriorly 

 toward postero-lateral angle ; a second longitudinal groove outside the first 

 divides branchial regions unequally. 



Front at base one-sixth as wide as distance between antero-lateral angles, 

 gradually narrowing to a broadly rounded extremity. Antero-lateral angle 

 little more than a right-angle; anterior third of side margin directed back 

 ward and a little outward ; the margin then turns abruptly inward at an 

 oblique angle and terminates above insertion of second pair of legs. 



Larger palm coarsely tuberculate outside ; inside an oblique ridge runs 

 from lower margin to a point above middle, then turns at a prominent 

 right angle toward supero-distal end of palm, where it joins the proximal 

 of the two ridges parallel to base of dactylus. 



31 PROC. BIOI,. Soc. WASH. VOL. XVII, 1904. (161) 



