1905.] FROM CHRISTMAS ISLAND. 539 
the fingers are provided, each, exactly as in that species, with a 
tuft of hair; the chele also much resemble those of Ptych. pilipes 
A. M.-Edw. from the Philippine Islands, but here the tufts of 
hair are wanting. Measured horizontally, the chele appear just 
as long as the distance between the antero-lateral angles of the 
carapace ; the palm is a little shorter than the fingers and, at their 
articulation, a little higher than long. The convex, outer surface 
of the palm, under a lens, appears very finely, but closely, punctate, 
though smooth to the naked eye; both the upper and the lower 
borders are rounded. The somewhat curved, tapering dactylus 
carries 7 or 8 small teeth, which are rather obtuse, except two or 
three near the tip; the immobile finger has 5 or 6 more conical 
teeth, which are larger than those of the dactylus, especially two 
or three in the middle. The fingers are finely and closely punctate, 
just like the palm; on the middle of the outer surface of the 
fixed finger the puncta are arranged in a longitudinal row that 
extends from the tip almost to the middle of the palm; a few 
larger, impressed puncta occur on the distal half of the index just 
above that row. As in Ptych. barbatus, each finger carries a close 
tuft of brown woolly hairs on the proximal half of its outer surface ; 
the tuft of the dactylus does not extend on to the upper border 
of the finger, and that of the fixed finger reaches only halfway 
between the teeth and the lower border. The tips of the fingers 
have horny margins: on the outer side of the tip of the fixed 
finger, close to and parallel with the horny edge, are seen a 
few short, stiffish setze, though much less numerous than in the 
female; on the tip of the dactylus they are perhaps worn off. 
The inner surface of the chelz (palm and fingers) is smooth and 
glabrous. 
The ambulatory legs are hairy on the upper side of their basal 
joints, and a few stiff sete occur on the lower surface of ischium 
and merus on either side of the articulation between these joints ; 
the posterior border of the last two joints is also setose, and rows 
of short sete: occur on the lower side of the propodites of the Ist 
and 2nd pair. For the rest, the upper and the lower borders of 
these legs are glabrous, devoid of the long hairs that are character- 
istic of Ptych. pilipes A. M.-Edw. The meropodites appear under 
a strong lens very finely granular, except those of the last pair, 
which are almost smooth and only punctate; the puncta are 
small and numerous, but three or four larger puncta in a longi- - 
tudinal row are found on the middle of the meropodites of the 
last pair. Just as in Ptych. barbatus A. M.-Kidw., there is no 
subterminal spine on the anterior border of the meropodites. 
The following joints are also punctate, and the dactyli are ridged 
longitudinally both on the upper and lower sides. 
On a yellow ground-colour the upper surface of carapace and 
legs is marked with innumerable, small, irregular spots of a dark 
purple colour, which on the epigastric and protogastric regions 
are almost confluent. 
Among the twelve species of Ptychognathus, certainly Ptych. 
