THE GEAPSOID CKABS OF AMEEICA, . 265 



Description. — A A'erj' small species. Carapace very little broader 

 than long, sides slightly convex and convergent to the acute antero- 

 lateral angles. Surface sloping gently downward to the four sides, 

 uneven, partly granulated, the cardiac and posterior gastric regions 

 well marked. Hepatic region depressed ; a transverse depression op- 

 posite the last lateral tooth. Three notches in the lateral margin 

 form three small teeth ; distance from first tooth to orbital angle one 

 and one-third times as great as distance from first to second tooth, 

 which last is twice as great as distance from second to third tooth. 

 The oblique raised line on the branchial region arises immediately 

 behind the last tooth. Abo\ e the bases of the last two legs a granu- 

 lated line runs parallel to the margin. 



Front distinctly less than half width of carapace, edge convex, 

 bilobed, outer angle obtuse. 



Antennules very large. The basal and succeeding joint of the 

 antenna together fill the orbital hiatus. The posterior margin of the 

 epistome is regularly arcuate as seen from below. Merus of outer 

 maxilliped much Avider than ischium, its outer margin very arcuate, 

 the palpus inserted not far from the middle. 



The stridulating ridge is crenulate, the crenules becoming finer 

 toward the outer end; it scrapes against a short portion of the distal 

 border of the inner margin of the arm. Arms short, stout, unarmed, 

 having a groove near the distal end. Wrist Avith inner margin 

 rounded. Chelae heavy, palms strongly widened distally, wider than 

 superior length, upper surface partly flat. Fingers rather narrow, 

 edges crenulate, a triangular gap at base in the male, n<> gap in 

 female, fingers subacute; several longitudinal rows of punctures, in- 

 closing on the outer side of the pollex a fairly distinct ridge. In the 

 female this ridge is more pronounced and is continued along the 

 palm. 



Legs slender, especially the dactyli; last pair much the shortest; 

 unarmed, except for a feeble tooth near the end of the merus joints; 

 furnished with a few hairs; dactyli grooved, with long slender horny 

 tips. 



Sixth segment of male abdomen shorter than fifth, seventh elongate, 

 very little widened at base. 



Measurements. — Male (22104), length of carapace 5.8, width 6, 

 width of front 2.5 mm.; length 7 lines (Dana). 



Range. — From Cape St. Roque, Brazil, to Gulf of San Matias, 

 Patagonia ; 10^ to 52 fathoms. 



Material examined. — See page 2GG. 



