538 BULLETIN 129', UNITED STATES NATIONAL MUSEUM 



margins. Carpus with five denticulated crests, Hand trigonous, 

 with 10 strong teeth on inner crest, 12 to 14 small granulated teeth 

 on outer margin, and 15 teeth increasing regularly in size toward 

 extremity on lower margin; upper surface with 2 rows of tubercles, 

 inner surface with 2 rows, and outer surface with 3 rows; all the 

 tubercles ornamented with from 2 to 5 granules. Fingers very 

 small, between a fourth and a fifth the length of palm; dactylus 

 when flexed almost at right angles with palm. Ambulatory legs com- 

 pressed, naked, polished, with a laminiform crest above; the merus 

 joints of posterior pair have a crest below, which has a lobe-like ex- 

 pansion at inner extremity. Abdomen tuberculated at sides, that 

 of male tapering slightly. 



Measurements. — -Male (18677), length of carapace 10.8, width of 

 same 11.6, length of cheliped 26 mm. 



Variations. — The two projections at ends of posterior margin 

 vary from very short, inconspicuous teeth to prominent teeth and 

 even spines, according to Stimpson. This is not dependent on sex, 

 as Stimpson thought, or on size; for in the museum collection there 

 are nine male specimens, of which three large ones have shallow 

 teeth, three small ones have well developed teeth, while the strongest 

 teeth occur on three specimens of different sizes, one small, one large 

 and one intermediate. In the single female the teeth are less evident 

 than in any of the males. The chelipeds show different degrees 

 of roughness; the merus may have an almost smooth upper surface 

 with only a line of granules near posterior edge, or the posterior 

 half of that surface may be pretty well covered with granulation. 

 The rougher specimens also show longer marginal teeth on the hand, 

 especially noticeable on the upper crest where the larger teeth may 

 be as long as wide and separated by sinuses which are rounded at 

 base instead of pointed. 



Range. — Bahama Banks, southern Florida, Gulf of Mexico, and 

 Caribbean Sea. Depth, 50 to 338 fathoms. 



Material examined. — See table, page 535. 



SOLENOLAMBRUS ARCUATUS Stimpson 



Solenolambrus arcuatus Stimpsoiv, Ann. Lye. Nat. Hist. New York, vol. 10, 

 1871, p. 101 [128] (type-locality, Panama; type not extant). 



? Solenolambrus typicus Gang, Boll. Soc. Nat. Napoli, ser. 1, vol. 3, 1889, p. 

 187, Panama; not <S. typicus Stimpson, 1871. 



Diagnosis. — Not more than four teeth on posterior and postero- 

 lateral margins. Two acute elevations on median line. A large 

 toothlet at middle of branchial ridge. Surfaces of hand smooth be- 

 tween crests; dactylus at right angles with palm. Sternum between 

 chelipeds without tubercles. 



