299 CRUSTACEA. 
first and second pair is armed near the distal end 
with a rather large sharp tooth, and often a se- 
cond smaller tooth is observed between the former and 
the distal end of the joint. The anterior border of the 
carpopodites and propodites of the ambulatory legs is en- 
tire, nowhere dentate, but the posterior margin of the 
propodites terminates in a sharp spinule at the distal end. 
The ambulatory legs are somewhat hairy. 
The cephalothorax of the largest specimen, a male, is 
8'/, millim. long and 8'/, millim. broad, and the larger 
or right chelipede measures 32 millim. The cephalothorax 
of the ova-bearing female specimen is 53/, millim. long 
and 61/, millim. broad, and its anterior legs have a length 
of about 17 millim. 
Petrol. leptocheles Heller is a closely allied species. I 
therefore sent a specimen of Petrol. Tenkatei to Mr. C. 
Koelbel of Vienna, who kindly compared it with the type 
specimens of Heller’s species and wrote me back that he 
considered the species from Flores to be a different one. 
In Petrol. leptocheles indeed the lateral margins of the 
front are more profoundly emarginate, sothat the 
lateral lobes are more distinct, the meropodites of all the 
ambulatory legs have no spinule on/their anterior 
margin, but are quite unarmed, and even the sharp 
teeth with which the posterior borders of the 
meropodites of the first and second pair of Pe- 
trol. Tenkatei are armed, are not found in Petrol. 
leptocheles. 
Perhaps our species may once prove to be identical with 
Petrol. hastatus Stimpson, but the lateral margins of the 
cephalothorax are described as scarcely cristate and the me- 
ropodites of the ambulatory legs are probably armed with 
more spinules as Stimpson says: »merus superne sparsim 
spinulosus”’. I therefore conclude, like also by the different 
habitat, Japan, that Stimpson’s species is another one, 
An adult specimen of Petrol. inermis Heller, described 
in my paper on the Crustacea of the Mergui Archipelago, 
Notes from the Leyden Museum, Vol. XV. 
