CRUSTACEA OF THE MERGUI ARCHIPELAGO. 49 
mobile finger is somewhat hairy and granular at the base, though 
much less than in A. obesus, the granules not extending beyond 
the proximal half of the finger. The outer surface of the fingers, 
the tips of which are pointed, is smooth. The inner surface of 
the hand is smooth, being only a little punctate at the base of the 
mobile finger. The smaller chelipede presents the same characters 
as the other. 
The ambulatory legs are precisely similar to those of A. obesus, 
being clothed with rather long yellow hairs, but they are some- 
what granular; the upper margin of the meropodites is minutely 
eranular, and somewhat larger acute granules are observed on the 
upper surface of the carpopodites and propodites. 
The cephalothorax of the largest specimen, a female, is 53 
millim. broad; and the species probably attains a larger size. 
37. AcrumMNus Nubus, A. W-Hdw. (PI. II. figs. 2 & 3.) 
Actumnus nudus, Alph. Milne-Edwards, Descript. de quelques espéces 
nouvelles de Crustacés Brachyures, Annal. Soc. Entom. de France, 4° sér, 
t. vil. 1867, p. 265. 
A single female specimen was collected in the Mergui seas. 
Prof. Milne-Edwards kindly identified it for me, and as his 
determination is doubtless correct, I now add a full description 
of the species. 
The specimen is nearly twice as large as that described by 
Milne-Edwards. The cephalothorax is rather narrow, the pro- 
portion of the breadth to the length being as 4 to 3. The 
upper surface is very convex longitudinally, and also somewhat 
declivous towards the lateral margins. Interregional grooves 
are almost wholly wanting: I only observe a faintly indicated, 
shallow, cervical suture, separating the gastric region from the 
hepatic and branchial regions, and the usual shallow, median, 
frontal furrow, bifurcated behind, which separates the slightly 
prominent epigastric lobes from one another. The front, the 
epigastric lobes, the gastric region, and especially the antero- 
lateral regions are covered with pearl-shaped granules ; on each 
side of the gastric region, ten or twelve of these granules are 
arranged in an arcuate line, with the convexity directed forward, 
which separates the antero-lateral region trom the postero- 
lateral. Each antero-lateral region (hepatic and epibranchial) is 
LINN. JOURN.— ZOOLOGY, VOL. XXII. A 
