192 
THE VOYA&E OF H.M.S. CHALLENGER. 
These specimens differ from what I will regard as the typical condition of the species 
(represented in de Haan’s figures of the adult) in the more slender chelipedes, which are 
less distinctly granulated and bear longer spines. I may add, that the posterior tooth of 
the antero-lateral margin is more distinctly spiniform ; the orbital margins are granu- 
lated, as is the basal joint of the antennae. The larger of the two females in the 
Challenger collection measures as follows : — 
• Adult $. 
Lines. 
Millims. 
Length of carapace, nearly . 
13 
27-5 
Breadth of carapace, .... 
17J 
37 
Thalamonyx, A. Milne Edwards. 
Thalamonyx, A. Milne Edwards, Nouv. Archiv. Mus. Hist. Nat., vol. ix. p. 168, 1873. 
This genus was established by A. Milne Edwards for two small forms, which I think 
are not specifically distinct, and which are perhaps best placed between Goniosoma and 
Thalamita, but also present evident affinities with Portunus, Bathynectes, and Lisso- 
carcinus. The description given above of Goniosoma will apply, in nearly all particulars, 
to Thalamonyx, but the carapace is narrower, and the antero-lateral margins less oblique 
than in many species of that genus. The front is only four-lobed, as in many species of 
Thalamita; the median lobes prominent, much wider than the lateral lobes, and 
divided by a small median notch or fissure. As in Goniosoma the basal antennal joint 
is produced at its antero-external angle into a process which occupies the interior hiatus 
of the orbit, but does not widely exclude the flagellum from it, as in Thalamita. The 
chelipedes are subequal and rather small. The merus-joint of the fifth (natatory) legs 
has a spine on its inferior margin, near the distal extremity ; the penultimate and 
terminal are dilated, as in Goniosoma and Thalamita. 
Thalamonyx danse, var. gracilijpes, A. Milne Edwards. 
Charyhdis (1), Dana, U.S. Explor. Exped., vol. xiii., Crust. 1, p. 287, pi. xvii. fig. 13, 1852. 
Goniosoma danse, A. Milne Edwards, Nouv. Archiv. Mus. Hist. Nat., vol. v. p. 153, pi vii. 
figs. 6, 7, 1869. 
Thalamonyx danse, A. Milne Edwards, op. cit., vol. ix. p. 170, 1873. 
Thalamita gracilipes, A. Milne Edwards, tom. cit., vol. ix. p. 169, pi. iv. fig. 3, 1873, var. 
Tongatabu, 18 fathoms (Station 172) ; a small male and two females were collected. 
?• 
Length of carapace, about 
Breadth of carapace, about 
Lines. Millims. 
3b 7-5 
4 9-5 
