vor. x¥,] . PROCEEDINGS OF THE NATIONAL MUSEUM. 269 
tubercles and a few granules near the lateral border of each branchial 
region. The surface above the posterior margin is covered with seat- 
tered granules. 
Rostral lobes very short, truncate, minutely crenulate; interspace 
broadly V-shaped. Upper orbital border with two small teeth. 
Antero-lateral spines four; the hepatic spine is subacute, with tuber- 
cles on its anterior border; branchial spines sharp, procurved, with a 
small spine anterior to the first and second. On the postero-lateral 
border just back of the lateral angle is a minute depressed spine. 
Basal antennal joint with three teeth visible from above; the tooth 
at the insertion of the next joint subacute; the one at the external 
angle, truncate; posterior tooth acute. Two additional teeth on the 
suborbital border; that next the postocular tooth acute; the other 
rounded, serrulate: Subhepatic and subbranchial regions tuberculate. 
Yhelipeds longer and larger than the next pair of legs. Merus with 
a row of five sharp spines above, two tubercles on the lower inner 
border, a triangle of three spines on the inner face, two spines on the 
upper anterior margin, and two on the outer surface near the anterior 
border. Carpus with two or three tubercles near the merus and two 
on the inner margin. Hand smooth, unarmed, with scattered punctures. 
Fingers slightly gaping at base with a tooth on the dactyl in both sexes. 
Ambulatory legs with meral and carpal joints spinose above; propodal 
joints and dactyls unarmed. 
Carapace and ambulatory legs finely pubescent. In the largest speci- 
men from Pernambuco the carapace is denuded, probably accidentally, 
and the surface under the lens presents a cellular structure with seat- 
tered punctures. Alcoholic specimens show traces of crimson. 
Length of carapace, 15 millimeters; width without spines, 15.5 mil- 
limeters. 
Mar Grande, Bay of Bahia, one specimen; Rio Formoso, Pernambuco, 
five specimens; collected by R. Rathbun, 1875-1877. 
This species, in the characters of the front, lateral spines, and legs, is 
very much like forceps, from which it is at once separated by the com- 
parative smoothness of the carapace. The sharp tooth on the basal 
antennal joint, forming part of the suborbital border, is conspicuous in 
this species. The preorbital angle is not advanced as in forceps, and 
the legs are less hairy. 
Mithrax forceps (A. Milne Edwards). 
Mithraculus forceps A. Milne Edwards, Miss. Sci. au Mexique, pt. 5,1, p. 109, pl. xxurt, 
fig. 1, 1875. 
Mithraculus hirsutipes Kingsley, Proc. Boston Soc. Nat. Hist., xx, p. 147, 1879; Proc. 
Acad. Nat. Sci. Phila., xxx1, p. 389, pl. xv, fig. 1, 1879. Heilprin, op. cit., p. 
318, 1888. 
Mithrax forceps Miers, Challenger Rept., Zool., Xvi1, pp. 87, 88, 1886. 
Mithrax hirsutipes Miers, op. cit., p. 87. 
A large series of specimens from nineteen different localities shows this 
species to be extremely variable. The small specimens show marked 
