REPOET ON THE BRACHYURA. 
77 
nothing from West Indian examples of the species 
in the collection of the British 
Museum. 
Adult S . 
Lines. Millims. 
Length of carapace and rostrum, 
Breadth of carapace, about 
Length of a chelipede, nearly 
Length of first ambulatory leg, 
35| 75 
17A 37-5 
35 74 
34 72 
Picroceroides, n. gen. 
The carapace is narrow and rounded behind, it is constricted behind the orbits, which 
are tubular and project laterally as in Mcicrocceloma ; the width at the orbits about equals 
the greatest width of the carapace at the branchial regions. The orbits have a long 
prseocular and a short postocular spine, and are emarginate above and below. The rostral 
spines are slender, divergent, and widely separated at the base. The post-abdomen is 
seven-jointed in both sexes, and is transversely ridged in the male ; the ridges correspond 
to similar elevations on the sternum, they are rounded and separated by deep depressions. 
The epistoma is transverse. The antennulary fossettes are small, deep and well defined ; 
the antennae have the basal joint (as in Pericera and Mcicrocceloma) very considerably 
enlarged, and armed on its exterior surface with a keel or crest placed immediately 
below the next joint, but the spine of the distal margin of this joint is obsolete and 
represented merely by a small tubercle ; the following joints of the antennae are slender, 
and the first mobile joint is partly concealed by the rostral spine. The exterior maxil- 
lipedes are small, with the merus-joints distally truncated, and with the antero-external 
angles rounded and the antero-internal angles emarginate. The chelipedes are moderately 
elongated and rather slender, with the palms slightly compressed, and more than twice 
as long as broad ; dactyli with an intermarginal hiatus at base. The ambulatory legs are 
very slender and of moderate length, with the joints subcylinclrical, without spines ; 
dactyli nearly straight. 
This genus is intermediate in position between Pericera and Macrocceloma ; from 
the former it is distinguished by the absence of lateral marginal spines of the carapace 
and the great lateral projection of the orbits, from the latter by the form and develop- 
ment of the rostral and orbital spines and by the absence of the distal spines of the basal 
antennal joints. 
It might with almost equal propriety be regarded as a subgenus of one or the other 
of these genera. 
Picroceroides tubularis, n. sp. (PI. X. fig. 1). 
The carapace is moderately convex, much longer than broad, but little dilated at the 
branchial regions. The interfrontal space is concave, the gastric regions somewhat 
