THE CANCROID CRABS OF AMERICA 317 



LOPHOXANTHUS LAMELLIPES (Stimpson) 



Plate 148, Figures 3 and 4 



Xantho lamellipes Stimpson, Ann. Lye. Nat. Hist. New York, vol. 7, 1860, 

 p. 205 [77] (type-locality, Cape St. Lucas; type in M.C.Z.). 



Lophoxanthus lamellipes A. Milne Edwards, Crust. Reg. Max., 1879, p. 256, 

 pi. 46, figs. 3, 3a. 



Diagnosis. — Carapace flat, octagonal. Chelipeds massive; carpus 

 broader than long; fingers high, not gaping. Legs broad, laminiform. 



Description. — Carapace smooth, somewhat octagonal; antero- 

 lateral margin having a strong angle or shoulder on the hepatic region 

 just before the indistinct cervical suture. Carapace very broad at 

 this shoulder; between it and the orbit the margin is thick, obtuse, 

 perfectly straight and smooth. Behind the shoulder-tooth and alniost 

 in the same longitudinal line there are two other small teeth, rather 

 sharp and crested. Front deflexed, surface reticulated, edge bilobed, 

 each lobe formed of a submedian lobe and an outer tooth. Sub- 

 hepatic regions reticulated, that is, covered with minute cavities, the 

 parietes of which form a fine network. Ischium of outer maxillipeds 

 with a deep longitudinal furrow not far from middle; merus with two 

 irregular depressions. Chelipeds angular, with reticulated surface 

 especially on merus and carpus; upper side of carpus somewhat 

 dilated, with a strong outer, inner, and posterior tooth or angle; 

 manus thick, higher than its superior length. Fingers high, not 

 gaping, marked with longitudinal rows of punctae, tip of immovable 

 finger curved upward; prehensile teeth shallow, tooth at middle of 

 propodal finger most prominent. Ambulatory legs much com- 

 pressed, almost laminiform, with sharp, smooth lamelliform crests 

 above, that on the carpus of the first two legs distinctly bilobed; the 

 carpus and propodus of these legs have also a longitudinal crest on 

 the side, the spaces between crests forming deep cavities. Sternum, 

 abdomen and inner side of legs pubescent. (After Stimpson.) 



Color. — Slate-colored, with the antero-lateral margins and cheli- 

 peds reddish-white. 



Measurements. — Male (50968), length of carapace 8.4, width of 

 same 13, fronto-orbital width 6.5, width of front 4 mm. 



Range. — West coast of Mexico to Ecuador. 



Material examined. — Cape St. Lucas, Lower California, Mexico; 

 John Xantus; 1 male, 1 female, cotypes (1254, M.C.Z.). 



La Paz, Lower California, Mexico; L. Belding; 1 male .(17287), 

 1 ovigerous female (17534). 



Clarion Island, Mexico; shore; Hanna and Jordan, California 

 Acad. Sci.; 1 young; returned. 



Panama; received June 10, 1862; C. F. Davis; 1 ovigerous female 

 (2342, M.C.Z.). 



Naos Island, Panama Bay; E. M. Keyser; 1 male (50968). 



