CKUSTACEA OF THE MERaUI AECSIPELAaO. 105 



66, Pinnotheres paevulfs, 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 atropurpicrea 

 and P. vexillwn, from King Island Bay. I refer them to Sfcimp- 

 son's Pinnotheres parvulus. 



This species closely resembles P. glolosus, Hombr. & Jacq. ( = 

 ohesus, 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. glohosus 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. glohosus 

 (Milne-Edwards, Ann. Sci. Nat. t. xx. 1853, pi. xi. fig. 6 a), and 

 are the longest of all the dactylopodites, being but little shorter 



