THE CAXCROID CRABS OF AJMEEICA 61 



eighth narrower than seventh, first and second equally advanced, 

 first very small, on a higher level than the second and bent so as to 

 form part of the orbital margin. Lateral spine long and narrow, 

 directed outward and upward; 20 to 25 denticles on its anterior 

 m^irgin. Posterior angles of carapace with a slender curved spine 

 directed upward, forward, and outward. 



Superior fissures of orbit open, V-shaped, as are also the two outer 

 fissures; one of these is in line with the second antero-lateral tooth, the 

 other is below, in the customary place; on the intervening lobe a 

 stridulating mechanism begins and continues to a point opposite the 

 penult lateral sinus, gradually curving away from the margin; the 

 striae are about 24 and become progressively shorter, the last being 

 only a granule. Inner suborbital tooth large, concave below; next it 

 a smaller tooth, followed by an oblique margin cut into 6 or 7 symmet- 

 rical denticles, situated so as to form 

 a continuation of the stridulating 

 apparatus. 



Chelipeds short and stout. An- 

 terior margin of merus denticulate 

 and with two spines and a tubercle, 

 the proximal spine narrower and 

 sharper than the other; a slender figure 9.— postuxus (portuxus) vocaxs, 

 spine at postero-distal angle; the male (esso), carapace 23.5 mm. wide, ven- 



•^ c 1 . TRAL VIEW TO SHOW STEIDrLATIXG RIDGE 



upper surface has a crescentic 



stridulating ridge halfway across its middle which plays against the 

 ridge on the carapace. Carinae of carpus and manus prominent, 

 denticidate; inner carpal spine large, outer small. Two spines on 

 manus, the supero-subdistal one a little smaller than the prominent 

 proximal one; 5 carinae on upper-outer surface; upper carina sinu- 

 ous, overhanging inner surface. Fingers thick at base, the large tooth 

 on each finger of the major chela strongly outstanding. Ambulatory 

 legs long and very slender. Merus of s%vimming leg small, about three 

 times as long as wide, sUghtly enlarged at middle, a slender spine 

 at postero-distal angle; propodus and dactylus elongate, the latter 

 with a terminal spine. Male abdomen after the third segment tri- 

 angular, not constricted. 



Measurements. — Male (6930), total length of carapace 11.8, \ndth of 

 same 23.5, width at anterior base of lateral spine 18, fronto-orbital 

 width 10, width of front 4.4 mm. Holotype (carapace only) (Paris 

 Mus.), length of carapace 22, width of same 43 mm. (A. Milne 

 Edwards) . 



Range. — West Indies; east Atlantic (Cape Verde Islands); South 

 Atlantic (Ascension Island). 



Material examined. — See table, page 62. 



