THE SPIDER CRABS OF AMERICA 541 



spines. Eight additional dorsal spines — two on each branchial ridge, 

 of which the posterior or marginal is the longer, one at each posterior 

 angle, and one on postero-lateral margin midway between the last 

 and branchial spine. Surface finely punctate. Sternum smooth be- 

 tween bases of chelipeds. Terminal segment of abdomen of male 

 much longer and distally narrower than in S. tijpicus, its sides deeply 

 concave. Merus of the outer maxillipeds narrower and more pro- 

 duced at antero-external angle than in S. typicus. Chelipeds similar 

 to those of S. typicus. The second, third, and fourth pairs of ambu- 

 latory legs more or less cristate below. 



Measurements. — Male, holotype, length of carapace 6, width of 

 same 7, length of cheliped 12 mm. 



Range. — Gulf of Mexico and Porto Rico. Depth, 45 to 60 fathoms. 



Material examined. — 



Gulf of Mexico: Off Cape San Bias, Florida; lat. 28° 44' 00" N.; 

 long. 85° 16' 00" W.; 60 fathoms; gy. S.; March 15, 1885; station 

 2404, Albatross; 1 male, holotype (18157). 



Porto Rico: Off entrance to San Juan; Battery on El Boqueron, 

 S. E. y2 E., 1^4 miles; 45 fathoms; S. M.; temp. 77° F.; January 13, 

 1899; station 6051, Fish Hawk; 1 male (24236). 



SOLENOLAMBRUS TENELLUS Stimpson 



Plate 194, figs. 3 and 4; plate 279, figs. 5-9 



Solenolamhrus tenellus Stimpson, Bull. Mus. Comp. Zool., vol. 2, 1871, 



p. 134 (tj'pe-localities, off Carysfort, Conch and French Reefs, 35 to 49 



fathoms; types not extant). 

 Pisolambrus nitidus A. Milne Edwards, Crust. R4g. Mex., 1878, p. 158, 



pi. 30, figs. 4— 4e (type-locality, Barbados, 100 fathoms; cotypes, Cat. 



No. 2943, M. C. Z.). " 



Diagnosis. — No spines or teeth on posterior or postero-lateral mar- 

 gins. Dorsal protuberances rounded. Eyes very large. Margins 

 of arm and hand serrated. Chelipeds three times as long as carapace. 



Description. — A small, delicate species. Carapace but little 

 broader than long, and about equally produced in front of and 

 behind the line of the lateral angles. Surface rather coarsely punc- 

 tate. Protuberances of carapace much less prominent than in typicus; 

 those of gastric and cardiac regions obtusely rounded, without 

 angular ridges; ridge of branchial region sufficiently well marked 

 near postero-lateral margin, but alm^ost obsolete anteriorly. Mar- 

 gins of carapace crenulated, the teeth being most distinct on the 

 flattened, expanded, and broadly rounded lateral angle, where they 

 are about six in number, not crenulated, and but little projecting, 

 being defined cliiefly by the impressed lines on the marginal limb. 

 Two or three denticulated teeth on hepatic region. Postero-lateral 

 margin slightly concave. Posterior margin convex; its lateral 



