THE GBAPSOID CRABS OF AMERICA. 295 



Measurements. Length of carapace 18.5, width of same 22, width 

 of front 13 mm. 



Locality. Brazil ; Pernamb,uco. 



SESARMA (SESARMA) BIDENTATUM Benedict. 



FRESH-WATER CRAB. 



Plate 80. 



Sesarma bidentata BENEDICT, Johns Hopkins Univ. Circ., vol. 11, 1892, p. 77 

 (type-locality, Kingston Harbor, Jamaica; holotype female, Cat. No. 

 17281, U.S.N.M.). 



Diagnosis. Carapace narrowed anteriorly. Side tooth acute. 

 Palm tuberculate. Legs narrow. 



Description. Distinctly narrowed from posterior to anterior 

 angles, regions distinct, surface coarsely punctate, and toward the 

 front and sides granulate. Lateral tooth acute, behind it a trace of 

 a second tooth. 



Front just half or a little more than half the fronto-orbital dis- 

 tance, five times as wide as high, superior lobes well marked, their 

 anterior margin zig-zag, the outer pair much narrower and more 

 advanced than inner pair; lower margin sinuous, in dorsal view bi- 

 lobed; sides parallel. 



Outer face of arm and wrist crossed by short granulate lines; an 

 obtuse angle near the distal end of the upper border of arm ; lower 

 margins marked by spinif orm tubercles ; inner angle of wrist rounded. 

 Palm of male swollen and tuberculate except near the fingers ; upper 

 margin a more or less interrupted line of granules ; inner surface in 

 part coarsely tuberculate. Fingers narrow, irregularly gaping; pre- 

 hensile teeth irregular, the largest one near the tip; upper surface 

 of dactylus spinulous for three-fourths its length. 



Legs narrow ; third leg a little more than twice the length of cara- 

 pace, its merus two and three-fourths times as long as wide. Tooth 

 on meropodites spinif orm; last two joints tomentose, especially on 

 the margins. 



Abdomen of male broadly triangular. 



Measurements. Male (32285), length of carapace 23.5, width of 

 same 28, width of front 12.6 mm. 



Habitat. Lives in fresh-water rivers and mountain streams, under 

 loose stones in the shallows. 



Range. Known only from Jamaica. To an altitude of 4,500 feet. 



Material examined. Jamaica : 



Small streams near Troy, about 2,000 feet altitude, found under 

 loose stones in the shallows; November, 1905; W. Harris; 4 males, 

 1 female (32285). 



Accompong (St. Elizabeth) ; P. W. Jarvis; 1 male (19052). 



