THE GKAPSOID CRABS OF AMERICA. 255 



to a little broader than long; strongly convex in both directions; 

 almost smooth ; faint oblique lines on the outer part of the branchial 

 region, and very short transverse lines on the anterior portion. The 

 front may be a little more, or a little less than half the width of the 

 carapace, edge convex, slightly bilobed, granulate. Orbits little 

 oblique. Lateral tooth obtusely angled, sometimes obsolete. Lower 

 margin of orbit granular. Tooth at inner angle equilateral, sub- 

 acute. 



Merus of outer maxillipeds much broader than long. 



Chelipeds equal. Inner margin of arm dentate, distal end 

 coarsely so. Inner angle of wrist subacute. Palms with several 

 oblique lines above and below, a longitudinal line on the pollex. con- 

 tinued feebly and brokenly on the palm. Pcllex with a prominence 

 near the middle of its prehensile edge. Fingers narrowly or not at 

 all gaping. 



Second and third legs subequal, one and one-half times as long as 

 carapace, fourth leg shortest. Merus joints with an inconspicuous 

 anterior subterminal tooth, and a few posterior denticles, which 

 diminish in strength from the first to the fourth pair, where they are 

 minute. Last three segments thorny and with a dense fringe of 

 hair on the anterior edge. 



Abdcmen of male regularly triangular from the middle of the 

 third segment to the end. 



Color. — Extremely variable. Usually irregularly mottled or 

 blotched with light greenish-yellow or pale j^ellow on a darker olive- 

 green ground color, the carapace thus imitating the olive-green 

 colors of the gulfweed {Sargassum) and the whitish patches of 

 Bryozoa (Bifiustra) with which the Sargassum is commonly cov- 

 ered (Verrill), 



For variation and color see page G71 and Plate VI of Murray and 

 Hjort, " Depths of the Ocean," 1912. 



Measurements. — Male (17712), length 18.9, width 18.7 mm. 



Ilahits and distribution. — Pelagic, common in gulfweed, especially 

 in the Sargasso Sea ; occasionally on turtles, floating logs and sticlis, 

 or jeliyfishes; and in living sponges. In all tropical and temperate 

 seas. 



Occasionally found on shore, as at Sakonnet Point, Rhode Island, 

 an egg-bearing female, under rocks; and at Salina Cruz, Mexico, on 

 sand beach. 



Material examined. — See pages 256 and 257. 



