THE SPIDER CRABS OF AMERICA 329 



Measurements. — Young male, holotype, total length of carapace 

 from posterior margin 13.3, width without spines 7.5, with spines 11.2 

 mm. 



Range. — Known only from the type-locality and unique specimen 

 from the Gulf of California, off Shoal Point, Mexico, near the mouth of 

 the Colorado River, lat. 31° 33' 00" N.; long. 114° 20' 30" W., lOJ^ 

 fathoms, fne. gy. S. brk. Sh., Mar. 26, 1889, station 3029, Albatross, 1 

 young male (16072). 



ReynarJcs. — ^Differs from all other species in the long, horizontal, 

 hepatic spine. 



LIBINIA ROSTRATA Bell 



Plate 122, fig. 2; plate 242 



Libinia rostrata Bell, Proc. Zool. Soc. London, vol. 3, 1835 (183G), p. 169 

 (type-locality, "ad oras Peruviae"; type not extant); Trans. Zool. Soc. 

 London, vol. 2, 1836, p. 42, pi. 8, fig. 3. 



Diagnosis. — Rostrum with long, wide-spread horns. Arms with 

 longitudinal rows of tubercles and spines. Three enlarged tubercles 

 in gape at base of fingers. 



Description (after Bell). — -Carapace almost globose, regions much 

 elevated, with numerous strong spines and tubercles, one longer than 

 the rest standing out horizontally on each branchial region. Antero- 

 lateral margin with 3 spines, while a fourth behind them forms the 

 commencement of a flattened ridge extending backwards to the pos- 

 terior margin. [These are undoubtedly submarginal, chiefly ptery- 

 gostomian spines.] Orbits with a strong preocular spine. Rostrum 

 very prominent, flattened, terminating in 2 strong divergent spines. 

 Chelipeds of male twice as long as body; arms furnished with 

 numerous obtuse spines [disposed in 3 rows, according to figure]; 

 wrists tuberculate; hands granulate; fingers toucliing each other only 

 at the rather acute points. 



According to Bell's figure, the arrangement of the dorsal protuber- 

 ances is as follows: A transverse row of 5 tubercles on the anterior 

 gastric region, with another median tubercle closely in advance; on 

 the mesogastric region- a small diamond of 4 tubercles placed length- 

 wise. Three other median tubercles, namely, genital, anterior car- 

 diac, and intestinal. On the posterior half of the branchial region 

 two longitudinal rows, the inner row of 2 tubercles, the outer row of 

 3 spines; on the anterior branchial region a triangle of 3 tul^ercles. 

 The rostral horns are so widespread that the width between their tips 

 is more than one and one-half times the width at base of rostrum. 

 On the basal half of the fingers in the gape there are 2 tubercles on 

 the dactylus and between them one on the fixed finger; distal half 

 of prehensile edges crenulate. The first ambulatory leg is not much 

 longer than the carapace. 



