214 DR. J G. DE MAN ON THE PODOPHTHALMOUS 
The anterior margins of the meropodites of the ambulatory 
legs are unarmed, but the posterior margins of the first two pairs 
are armed with an acute spine near their distal ends. In one 
large individual the latter margins are armed with two spines 
at the distal end, as a second smaller spinule occurs between 
the described one and the articulation. The posterior margins 
of the meropodites of the third pair of ambulatory legs (the 
penultimate pair of legs) are unarmed. The propodites of 
the first three pairs of ambulatory legs are armed with a small 
spinule in the middle, and with one somewhat larger and with 
two similar small spinules at the distal ends of their posterior 
margin; these spinules are all mobile. The dactylopodites of 
the first three pairs of ambulatory legs are short, terminate in 
a black horny claw, and are armed on their posterior or inner 
margins with two or three spinules. The ambulatory legs are 
somewhat hairy. 
The specimens are of a yellowish-red colour, and marked with 
numerous sinall red spots on the carapace and on the ambulatory 
legs, and with some larger red spots on the anterior legs. 
Mr. Miers has lately pointed out (Voyage of H.MLS. ¢ Alert,’ 
p. 269) that the carapace of Porcellana (Petrolisthes) Lumarckit, 
Leach, from Australia, is armed with an epibranchial spine. Tam 
indebted to Prof. Milne-Edwards for a typical specimen of Por- 
cellana (Petrolisthes) Lamarckii, M.-Kdw. (Hist. Nat. des Crust. 
t. 1. p. 251), from New Ireland, and having carefully examined 
it, I am disposed to regard this form ag merely a variety of 
P.inermis, Heller, as the foregoing typical specimen differs from 
the Mergui specimens of P. inermis only in one character, viz., 
the presence of two small spinules on the anterior margins 
of the meropodites of the second and third pair of ambulatory 
legs. 
Petrolisthes hastatus, Stimps., from Japan, seems to be iden- 
tical with the New Ireland species. If this and the foregoing 
supposition prove to be true, then this species must bear the 
name of P. hastata, Stimps. 
The cephalothorax of the largest Mergui specimen is nearly 
12 millim. long. 
Porcellana inermis, Heller, has hitherto been recorded only 
from the Nicobar Islands. 
