THE CANCROID CRABS OF AMERICA 525 



The punctae probably served as hair sockets. Posterior extremity 

 very narrow. Areolets not protuberant. Median frontal channel 

 rather deep and conspicuous. Front broad, most advanced at middle, 

 lobes with slightly concave, nearly straight oblique margin, separated 

 from the supra-orbital margin by a small notch; its margin is granu- 

 lated and has a slight channel running parallel with it and separating 

 it from the frontal region. Orbital margin unarmed except by small 

 tubercles or granules, according to Stimpson, and has a single slight 

 fissure at the middle above. In the dried specimen (60223) there is 

 a sharp spinule on the upper margin of each orbit a little within or- 

 anterior to the fissure; also two spines on lobe at inner lower angle. 

 Antero-lateral margin sharply defined, almost limbed; armed with 

 three very slightly prominent spines besides angle of orbit and a 

 broad lobe posterior to it, neither of which project beyond the general 

 outline. The three teeth are each composed of two or three denticles 

 of about the size of the dorsal tubercles. Last tooth minute and 

 almost directly behind and above the one in front of it and is easily 

 overlooked. There is no subhepatic tooth but the region is finely 

 granulate. 



Ridges of endostome sufficiently marked. Chelipeds large, bris- 

 tling with spines and acute tubercles. The spines occupy the upper 

 surface of carpus and manus, the longest spines on the margin, five 

 or six on margin of manus ; lower down on the outer surface the spines 

 become sharp tubercles which toward the smooth lower margin are 

 scarcely more than granules. The ridges of both fingers are granulate 

 for half their length. 



Color. — Chelipeds rosy red in a dried specimen. 



Measurements. — Ovigerous female, dried (60223), length of cara- 

 pace 3.9, width of same 5, posterior width of same 3.7, fronto-orbital 

 width 4, width of front 1.8 mm. Male type, length 4 mm. (0.16 inch), 

 width 5 mm. (0.2 inch). 



Range. — West coast of Mexico: Cape St. Lucas to Manzanillo. 



Material examined. — Manzanillo, State of Colima; on drifted pile; 

 July 17, 1913; C. R. Orcutt; 1 ovigerous female, 2 young (60223). 



Genus LOBOPILUMNUS A. Milne Edwards 



LohoTpihimnus A. Milne Edwards, Crust. Reg. Mex., 1880, p. 297; type, L. 

 agassizii (Stimpson) . 



Closely allied to Pilumnus. Carapace unusually thick, much 

 swollen and deeply lobulate anteriorly. Front consisting of two 

 rounded lobes plainly separated from the inner orbital angles by a 

 rectangular emargination. Orbits with two fissures above and a 

 third below the outer angle. Antero-lateral margin cut into three 

 large teeth behind the orbital tooth or lobe; they are roughened by 

 numerous spinules or tubercles. A tubercle or small tooth on sub- 



