1895.] 
A. Alcock — Garcinoloijical Fauna of India. 
235 
The external maxillipeds liave the merns as broad as the ischium, 
and the palp attached to the internal angle of the merns. 
The chelipeds in the adult male are somewhat stouter than the 
other legs, have the palm short and enlarged, and the fingers arched 
and meeting only at tip : in the female they are slenderer than the other 
legs, have the palm slender, and the fingers closely apposable through¬ 
out. The ambulatory legs are stout, and have the dorsal surface sharply 
nodose or coarsely spinose. 
The abdomen in both sexes consists of seven distinct segments. 
This genus, which appears to me to be but slightly distinct from Pisa 
(e.g., Pisa corallina ), Riss., shows the transition towards Tiarinia in the 
next group. 
That it should be grouped with Tiarinia and Macrocoeloma , as it is 
by Miers ( loc . cit.f I cannot agree, since Tiarinia has complete orbits 
and an enormously broad basal antennal joint, which Tylocarcinus has not. 
The type of Tylocarcinus , namely T. styx (Herbst) = MicropJirys 
styx A. Milne-Edwards, is placed by the latter author (Nouv. Archiv. 
du Mus., VIII. 1872, p. 217) between Picrocerus and Griocarcinus on 
the one hand and Hyastenus on the other; and this seems to me to be a 
very natural position. 
Tylocarcinus styx (Herbst). 
Cancer styx, Herbst, Krabben, III. iii. 53, pi. viii. fig. 6 (“ nur klein”). 
[Pisa styx, Latr. Encyc., X. 141.] 
Pisa styx, Milne-Edwards, Hist. Nat. Crust. I. 308. 
Arctopsis styx, Adams and White, c Samarang’ Crust, p. 10; and A. Milne- 
Edwards, in Maillard’s L’ile Reunion, Annexe F, p. 6. 
Milnia styx, Stimpson, Ann. Lyc. Nat. Hist. New York, Vol. VII. 1862, p. 180. 
Microphrys styx, A. Milne-Edwards in Archiv. du Mus. VIII. J872, p. 247, pi. 
xi. fig. 4. 
Tylocarcinus styx, Miers, Ann. Mag. Nat. Hist. 1879, Vol. IV. p. 14. 
Pisa styx, Richters, Mobius, Meeresf. Maurit., p. 141. 
Tylocarcinus styx, de Man, Notes Leyden Mus., Vol. III. 1881, p. 94; and 
Archiv. fur Naturges. LIII. 1887, p. 228; and Ortmann, Zool. Jahrb. Syst. etc. 
VII. 1893, p. 62; and Henderson, Trans. Linn. Soc., Zool., 1893, p.349. 
Carapace subpyriform and covered with rounded tubercles, among 
which the following are distinct:—two in the inter-orbital space; four 
in a transverse series on the front part of the gastric region, followed 
by three in a triangle; one in the groove between the gastric and cardiac 
regions, and three in a triangle on the latter region; two, side by side, 
on the intestinal region ; and three on the posterior margin. Besides 
these there are several on either hepatic region, and many on the bran¬ 
chial regions. 
J. ii. 30 
