a 
CRUSTACEA OF THE MERGUI ARCHIPELAGO. 105 
66. PrynotHEREs PARVULUS, Stimps. 
Pinnotheres parvulus, Stimpson, Proceed. Acad. Natural Sciences 
‘Philadelphia, 1858, p. 108. 
The Collection contains three other specimens of a Pinno- 
theres, all provided with eggs, and found in Pinna atropurpurea 
and P. vexillum, from King Island Bay. I refer them to Stimp- 
son’s Pinnotheres parvulus. 
This species closely resembles P. globosus, Hombr. & Jacq. (= 
obesus, Dana), in its outer appearance; but it is distinguished 
from it by the relative length of the ambulatory legs and of 
their joints. In P. globosus these appendages are very slender 
and successively decrease in length, those of the third, or penulti- 
mate pair, being a little shorter than those of the antepenul- 
timate pair, and the fourth or last pair is the shortest of all, 
The dactylopodites of all the ambulatory legs have nearly the 
same length in Dana’s figure. 
In these specimens, on the contrary, the ambulatory legs of the 
first pair are the shortest of all, those of the second pair are but 
little longer; the legs of the third pair, however, are much longer 
than the two preceding pairs and are the longest of all, for the 
legs of the fourth pair, though distinctly longer than those of the 
first two pairs, are shorter than the legs of the penultimate 
pair. The meropodites of all the ambulatory legs have nearly 
the same length, except those of the third pair, which are once 
and a half as long as those of the other legs. The carpopodites 
of the legs of the third pair are almost twice as long as those of 
the first pair, and the carpopodites of the last pair are a little 
shorter than those of the first pair. The propodites also gradually 
increase in length from the first to the third pair, those of the 
latter being nearly twice as long as the propodites of the first 
pair of legs. The propodites of the fourth pair are nearly as 
long as the meropodites of the same legs, and a little shorter 
than the propodites of the penultimate pair. 
The dactylopodites of the first two pairs are rather short, 
scarcely surpassing half the length of the propodites of these 
legs. Those of the third pair are distinctly longer, measuring 
about two thirds of the propodites of these legs. The dactylo- 
podites of the last pair are very similar to those of P. globosus 
(Milne-Edwards, Ann. Sci. Nat. t. xx. 1853, pl. xi. fig. 6 a), and 
are the longest of all the dactylopodites, being but little shorter 
