Goree Island, Senegambia. 215 
below and on its inner surface; fingers rather obscurely 
toothed on their inner margins, of a deep black colour, the 
coloration not extending along the inner and outer surfaces of 
the palm; the mobile finger is longitudinally channelled above, 
but without spinules or tubercles near its base. Ambulatory 
legs short, compressed, with only a few hairs on the upper 
margins of the merus joints; terminal joints clothed with a 
short dense pubescence. Colour in the typical example 
coppery red, paler below. Length of carapace about 7 lines 
(15 millim.), greatest breadth nearly 11 lines (23 millim.). 
The single specimen in the collection is an adult male. In 
the pitted carapace and chelipedes, and in the strongly defined 
inequalities of the carapace, this species more nearly resembles 
Aanthodius than Leptodius; but it presents no traces of the 
palatal ridges which are characteristic of the former genus 
and, indeed, constitute its sole claim to generic distinctness. 
As these ridges in Xanthodius are sometimes imperfectly de- 
fined, it may be necessary to unite the two genera, as has been 
done by Prof. A. Milne-Edwards. As compared with the 
West-Indian Xanthodius americanus, Saussure, Leptodius 
punctatus has the carapace somewhat less convex toward the 
frontal and antero-lateral margins, the lobulations of the cara- 
pace less prominent and separated by wider depressions. In 
both specimens of Leptodius punctatus examined the right 
chelipede is but little larger than the left. 
The differences, however, between the West-Indian and 
African forms are so slight that, but for the single character of 
the absence of the palatal ridges, I should have considered 
L. punctatus a mere variety of X. americanus. L. punctatus 
further resembles Xanthodius, and differs from most species of 
Leptodius, in that the black coloration of the fingers does not 
extend along the inner or outer surface of the hands. There 
is in the British-Museum collection a male, preserved dry, 
from the west coast of Africa, in which the frontal lobes are 
obsolete*. 
* Leptodius Macandree, sp.n. (PI. XIII. fig. 4.) 
There is in the collection of the British Museum a single specimen of 
a species of Leptodius from the Canaries, which is very distinct from the 
preceding and from all others that I have examined. It may be briefly 
diagnosed as follows:—Carapace flat above, with scarcely any traces of 
surface prominences or depressions; slight sulci, however, are observable, 
which originate at the bases of the third and fourth antero-lateral mar- 
ginal teeth. Frontal margin divided by a median notch into two broad 
truncated lobes, from which the little prominent internal orbital angles 
are separated by a notch; the teeth at the exterior orbital angles and the 
first pair of antero-lateral-marginal teeth are obsolete, the three posterior 
teeth of the antero-lateral margins distinct. Chelipedes robust ; carpus 
