1895.] 
A. Alcock— Garcinological Fauna of India. 
181 
flated club-shaped palm : in the female very short and slender. Ambu¬ 
latory legs long, with remarkably thin compressed joints: some of the 
legs spiny. 
Abdomen in both sexes with all the segments separate. 
This genus appears to be very closely related to Macrocheira. 
Platymaia wyville-thomsoni , Miers. 
Platymaia wyville-thomsoni , Miers, ‘ Challenger’ Brachyura, p. 13, pi. ii. fig. 1. 
Platymaia ivyville-thomsoni, Wood-Mason and Alcock, Ann. Mag. Nat. Hist., 
March, 1891, p. 258, and May, 1894, p. 401. 
Carapace transversely sub-circular with the cervical grove well 
defined: its surface ranging from spinate (in the young) to nearly 
smooth (in old adults). The rostrum, which is so short as not to break 
beyond the general outline, consists of three stout spines of equal size, 
the middle one being the horizontally projecting interanteunulary 
spine. 
The hepatic region of the carapace bears (in the adult) a nearly 
vertically disposed row of three spines, against the upper one of which 
the eye is retractile. 
The eye-stalks are short, and the eyes large and oval. The antennae 
are about one-third the length of the carapace, and are plainly visible, 
in almost the whole of their extent, from above: the joints of the pedun¬ 
cle are short slender and cylindrical, the basal joint being perfectly free. 
The external maxillipeds have the meropodite narrow (about half 
the breadth of the ischiopodite) and giving attachment to the coarse 
palp at the summit: both meropodite and ischiopodite are spiny. 
The chelipeds vary considerably according to sex : in both sexes 
they are spiny up to the base of the fingers ; but whereas in the female 
and young male they are much slenderer than any of the legs and 
are not longer than the carapace, in the adult male they are from two 
to three times the length of the carapace and are much stouter than 
any of the legs — especially as regards the palm, which is swollen and 
club-shaped. The 2nd to 5th pairs of legs are long and slender, with 
the joints thin and compressed, the propodites being blade-like. 
The 2nd pair, which are from 3f (female) to h\ (male) times the 
length of the carapace, are remarkable for their propodite and 
dactylus, the front edge of which bears a double comb of enormous 
spines, the posterior edge also being spinulate: both edges of the 
merus and carpus also are distantly spinulate. The 3rd and 4th pairs 
have the front edge of the merus distantly spinulate, and they, as well 
as the 5th pair, have the front edge of the razor-like merus closely 
fringed with long stiff hairs. 
