78 
THE VOYAGE OF H.M.S. CHALLENGER. 
elevated and obscurely tuberculated ; the cardiac region bears a rounded prominence 
and the intestinal region (usually) a small spine ; the cervical and branchio-cardiae 
sutures are continuous, and form a longitudinal sinus, separating the branchial from the 
gastric and cardiac regions. The tubular orbits project laterally to a remarkable degree, 
and each bears a very long prseocular, and a small postocular spine, and has two notches 
in the inferior and one in the superior margin. The rostral spines (in the adult male) 
exceed half the length of the carapace ; they are very slender, slightly curved, laterally 
divergent, and widely remote from one another at the base. The sternum (in the male) 
has three deep transverse fossae on each side of the post-abdomen, whose segments, also, 
are narrow and transversely ridged. The antennulary fossettes are very small ; the basal 
joint of the antennae, which is very greatly dilated, and coalescent with the surrounding 
parts of the carapace, is without spines, but has a small nearly longitudinal crest near its 
distal extremity below the following joint ; there is also a small tubercle on the distal 
margin which forms part of the wall of the tubular orbit. The ischium of the outer 
maxillipedes is longitudinally concave on its outer surface ; the merus is distally trun- 
cated, very distinctly notched at its antero-internal angle. The chelipedes are slender 
and somewhat elongated (in the adult male); the merus-joint subcylindrical and unevenly 
granulated ; carpus also granulated ; palm somewhat compressed but not carinated, it is 
granulated on its upper margin, and more distinctly on the inner than on the outer surface, 
which has a slight longitudinal depression near to the upper margin ; the fingers are 
somewhat curved and meet on their distal halves, the mobile finger has a strong tubercle 
on its inner margin near to the base. The ambulatory legs are extremely slender, and 
decrease successively in length ; their dactyli are slightly arcuate. 
The carapace and limbs (except the chelipedes) are rather thinly pubescent, the 
margins of the rostrum and of the free peduncular joints of the antennas have some longer 
hairs, some of which are clavate. Colour (in 
dark brown or black. 
spirit) yellowish-brown ; tips of the fingers 
Adult d • 
Lines. 
Millims. 
Length of carapace, about 
n 
16 
Breadth at branchial regions, . 
5 
11 
Length of rostral spine, 
5 
11 
Length of chelipede, .... 
14 
30 
Length of first ambulatory leg, 
13J 
29 
Fernando Noronha (shallow water), two males and an adult female; Bahia (shallow 
water), an adult male and female. 
