REPORT OR THE BRACHYURA. 
197 
excepted) are subequal, the first a very little larger than the others ; the fourth is repre- 
sented by a mere rudiment ; the postero-lateral angles of the carapace are rounded. The 
basal antennal joint is armed with a minutely granulated ridge. The chelipedes in the 
female are pubescent and rather slender ; the merus-joint is armed with two spines (and 
a smaller denticle) on its anterior margin, and a strong triangular lobe or tooth at the 
distal end of its inferior (not posterior) margin ; its posterior margin is rounded and 
entire ; the wrist has a strong spine on its inner margin, and three small spinules on 
its outer surface ; the palm has four spines, one basal near the articulation with the 
wrist, one distal at the base of the dactylus, one (longer) behind this on the inner and 
upper margin, and one on the upper surface ; the fingers are somewhat longer than the 
palm, and are armed, as usual in the genus, with irregularly alternating teeth ; the 
ambulatory legs are of moderate length (the third the longest), compressed and slightly 
pubescent ; the merus of the fifth or swimming legs is armed on its inferior margin with a 
strong spine placed at some distance behind the distal extremity ; the penultimate joint, 
as already stated, is unarmed ; the terminal joint is ciliated, ovate, and mucronate at its 
distal extremity. 
Adult $ . 
Lines. 
Millims. 
Length of carapace, about .... 
41 
9-5 
Breadth of carapace, ..... 
61 
13-5 
Length of a chelipede, ..... 
81 
18 
Length of third ambulatory leg, about . 
8 
17-5 
Off Nukalofa, Tongatabu, 18 fathoms (Station 172). An adult and a smaller female. 1 
This species is very nearly allied to the foregoing, which it resembles in its six-lobed 
front, and in the form of the carapace, but it is distinguished by the following characters : 
the carapace is narrower ; the frontal lobes, as a reference to the figure will show, are of 
different shape ; the fourth antero-lateral spine is rudimentary ; the basal antennal joint 
is nearly smooth, and the inferior margin of the penultimate joint of the fifth ambulatory 
legs is not denticulated or spinuliferous as in Thalamita intermedia. 
§§§ Thalamitse with Eight-lobed front. 
Thalamita 'prymna. 
1 Cancer prymna, Herbst, Naturgesch. tier Krabben u. Krebse, iii. Heft. iii. p. 41, pi. lvii. 
fig. 2, 1803. 
1 Portunus {Thalamita) prymna (var. /?.), de Haan, Crust, in v. Siebold, Fauna Japonica, pp. 10, 43. 
pi. xii. fig. 2, 1833. 
Thalamita prymna, Milne-Edwards, Hist. Hat. Crust., vol. i. p. 461, 1834. 
„ „ A. Milne Edwards, Arehiv. Mus. Hist. Nat., vol. x. p. 360, 1861, 
et synonyma. 
Tongatabu (on the reefs), an adult female; Ternate, 15th October, 1874, an adult 
male. 
1 The figure is restored from the two specimens, neither being perfect. 
