THE GBAPSOID CBABS OF AMEEICA. 296 



Measurements. — Length of carapace 18.6, width of same 22, width 

 of front 13 min. 



Locality. — ^Brazil ; Pernambuco. 



SESARMA (SESARMA) BIDENTATUM Benedict. 



FRESH-WATER CRAB. 



Plate 80. 



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

 (type-locality, Kingston Harboi-, 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 meriis 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. 



Ilahitat. — Lives in fresh-water rivers and mountain streams, imder 

 loose stones in the shallows. 



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



Material examined. — Jamaica : 



Small streams near Tro}', 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). 



