REPORT ON THE BRACHYURA. 
145 
To the description of Stimpson I may add the following: — 
This specimen (preserved in spirit) is yellowish ; the carapace and chelipedes are 
thickly punctulated with minute purple spots, which are very indistinct on the upper 
surface of the palm, and are obliterated on its outer surface ; the fingers purplish-brown, 
the coloration not extending over the inner and outer surface of the palm. Stimpson 
says nothing with regard to the coloration of his types. 
The carapace and chelipedes are smooth and naked except for a few inconspicuous 
hairs on the interior surface of the carpus; in this particular this species differs altogether 
from Pilumnus, but the ambulatory legs are slightly hairy. 
$ . Lines. Millims. 
Length of carapace, ....... 2J 5 
Breadth of carapace, . . . . . . .3 6 - 5 
Pilumnus , Leach. 
Pilumnus , Leach, Trans. Linn. Soc. Lond., vol. xi. p. 321, 1815. 
„ Milne-Edwards (pt.). Hist. Nat. Crust., vol. i. p. 415, 1834. 
Acanthus, Lockington, Proc. Calif. Acad. Nat. Sci., vol. vii. pt. i. p. 32, 1876. 
Parapilumnus, Eupilumnus (subgenera), Kossmann, Malacostraca in zool. Ergebn. einer Reise 
Kiistengeb. d. rothen Meeres (erste Halfte), p. 38, 1877 ; not Eupilumnus, Kingsley, Proc. 
Acad. Nat. Sci. Philad., p. 397, 1879. 
Carapace longitudinally convex, little broader than long, with the regions indistinctly 
defined ; it is thickly covered with hair on the dorsal surface, which extends also over 
the chelipedes and ambulatory legs, but not lobulated as in Lobopilumnus ; the antero- 
lateral margins are regularly arcuated, shorter than the postero-lateral margins, and are 
normally armed with short spines in place of the usual antero-lateral teeth ; the orbital 
margins are sometimes entire, sometimes spinuliferous ; the front is rather narrow and 
its anterior margin is usually spinuliferous or granulated and divided into two rounded 
lobes by a median emargination, exterior to each of which is usually a smaller lobe or 
tooth. The endostome is usually very distinctly longitudinally carinated. The post- 
abdomen of the male is distinctly seven-jointed, and its base usually occupies the whole 
width of the sternum, between the fifth ambulatory legs. The eyes are of moderate 
length. The basal antennal joint is short and slender, and barely reaches the infero- 
lateral frontal process, or sometimes falls short of it ; the next joint lies within the 
interior orbital hiatus. The merus of the endognath of the exterior maxillipedes is 
distally truncated, and in the typical species is not narrower than the ischium-joint. 
The chelipedes are moderately robust and usually unequal, with the merus-joint short 
and trigonous, the carpus and palm more or less granulated and spinuliferous on the 
superior margin and exterior surface ; fingers distally acute or subacute, and dentated on 
the inner margins ; ambulatory legs of moderate length, slightly compressed, but not 
(zool. chall. exp. — PART xlix. — 1886.) Ccc 19 
