THE GEAPSOID CEABS OF AMERICA. 315 



Description. Carapace a little longer than broad, and slightly 

 narrower in front than behind; surface very rough with pits and 

 wrinkles, and in the anterior third with granules which are coarse 

 and scaly, except behind the orbits, where they are very fine. 



Front equaling in width half the carapace, vertical; the projecting 

 edge only is visible in dorsal view, sides parallel, median sinus ex- 

 tremely wide and deep, each lobe faintly bilobed; supra-frontal 

 lobes subequal, deeply separated. 



Upper margin of orbit slightly convex; outer angle small, acute. 



Chelipeds small, very rough with sharp rugae on the arm, and 

 sharp granules on wrist and swollen hand. Arm with a small distal 

 expansion on the inner margin. Fingers little gaping, their pre- 

 hensile edges not very unevenly dentate. 



Legs long and narrow, third pair two and one-third times as long 

 as carapace, its merus two and two-thirds times as long as wide. 

 Merus joints narrowing from the middle toward the distal end. 



Abdomen of male oblong-triangular, appendages of first segment 

 much enlarged in their terminal third. 



Measurements. Male (32314), length of carapace 14.4, width of 

 same 14, anterior width 13.9, width of front 7.5 mm. 



Range. From Costa Rica (west side) to Bay of Panama. 



Habit. Lives in mangroves (Tristan). 



Material examined. 



Punta Arenas, Costa Rica; 1 male, 2 females (Copenhagen Mus.). 



Boca del Jesus Maria, Costa Rica; Apr., 1905; P. Biolley and 

 J. F. Tristan; 1 male, 1 female (32314). 



Santo Domingo, Gulf of Dolce, Costa Rica; Apr., 1896; H. Pit- 

 tier; 1 male, 1 female (19437). 



Taboga Island, Bay of Panama: May 12-15, 1911; Meek and 

 Hildebrand; 1 female ovig. (44175). June, 1914; J. Zetek; 1 male 

 (48789). 



Pearl Islands, Bay of Panama ; 1866 ; F. H. Bradley ; 1 male holo- 

 type (659, P.M.Y.U.). 



SESARMA (HOLOMETOPUS) HANSEXI Rathbun. 



Plate 87, fig. 1. 



Sesarma (Holometopus) hanseni RATHBUN, Proc. Biol. Soc. Washington, 

 vol. 11, 1897, p. 92 (type-locality, West Indies; male holotype in Copen- 

 hagen Mus.)- 



Diagnosis. Carapace transverse, broadest anteriorly, smooth. 

 Hand with crest above. 



Description. Carapace much broader than long, broader anteri- 

 orly than posteriorly. Regions well marked; mesogastric very wide 



