THE SPIDER CRABS OF AMERICA 



185 



Fig 



72.— LErCirPA PENTAGOSA 

 (471 19), MAXILLIFED, X 8.4 



interval. A very small preorbital tooth. Antefo-lateral margins 

 of carapace very thin, a little reflexed, four-toothed or angulately 

 undulate, the teeth unequal, the first tootlf equivalent to the postor- 

 bital angle, the fourth tooth forming the po.stlateral angle of the 

 carapace. Pterygostomian region usually two-toothed or spined. 

 Basal article of antennae armed outside with a^prominent crest, end- 

 ing forward in a small tooth and followed behind l)y a spiny tubercle. 



Chelipeds stout, cristate above; manus 

 compressed; fingers curved down, edges 

 crenulate, when closed, leaving a narrow 

 gape in basal half or more. Legs cristate 

 above except on dactjdus; the latter finely 

 denticulate below. 



Color. — Pale gray (Milne Edwards), 

 Tawny yellow (Milne Edwards and Lucas) . 



Measurements. — Largest male (2115, M. 

 C. Z.), length of carapace to tip of horn 23, 

 width 20.4 mm. 



Variations. — Varies in width of carapace, 

 prominence of lateral teeth, acuteness and 

 divergence of rostral horns. Average indi- 

 viduals have the ensenadae form (Edwards 

 and Lucas, fig. 3). 



Range.— ¥rom. Cape St. Roque, Brazil, to Patagonia, to Chile; 

 Magdalena Bay, Lower California, Mexico. Depth, 7 to 52 fathoms. 



Material examined. — See table, page 186. 



Genus SPHENOCARCINUS A. Milne Edwards 



Sphenocardnus A. Milne Edwards, Crust. R6g. Mex., 1S75, explanation 

 of pi. 17, fig. 5; 1878, p. 135; type, S. corrosus A. Milne Edwards. 



Oxypleurodon Miers, Challenger Kept., Zool., vol. 17, 1SS6, p. 38; type, 

 0. stimpsoni Miers. 



Carapace elongate-subpentagonal, broad behind, tapering in 

 front to a rostrum which ma}' be long and simple to near the tip 

 or formed of two spines either contiguous or divergent. Surface of 

 carapace usually sj^mmetrically and deeply honeycombed by broad, 

 deep channels which leave symmetrical tubercles often with over- 

 hanging edges between them. No true preocular and postocular 

 spines, but the eye is deeply sunk between two low, smooth excres- 

 cences which are preocular and postocular in position. Basal antennal 

 segment truncate-triangular; antennary flagella completely hidden 

 beneath the rostrum. Epistome long and narrow. External maxilli- 

 peds with the merus as broad as the ischium, somewhat dilated at 

 the antero-external angle, and usually slightly excavated at the 

 antero-internal angle for the insertion of the small palp. 



Chelipeds not much stouter but shorter than the next pair of legs 

 which are the shortest of the ambulatories; the dactyli of the legs, 



