CRUSTACEA. 297 



peduncles of the antenmo are very short, completely concealed 

 beneath the large basal scales, which reach slightly beyond the an- 

 tcnnal peduncles, narrow to their apices, and have a small spinule 

 at the distal ends of their outer margins. The outer maxillipedes 

 are rather robust and elongated, reaching, when thrown forward, 

 almost to the apices of the antennal scales. The first legs are much 

 shorter than the following, with the joints compressed, the dactyli 

 acute, and the basus and ischium-joints have each a small spine at 

 the distal ends of their inner margins; the second and third cheli- 

 pedes are slender (the hasus-joinl of the second legs bears a small 

 spine) ; the third are longer than the second ; the fourth legs are 

 slender and rarely as long as the third ; the fifth are imperfect. 

 The rami of the uropoda are narrow, and reach about to the end of 

 the terminal segment ; the outer has the lateral margins nearly 

 parallel ; in the inner ramus they converge very slightly to the 

 rounded extremity. Colour (in spirit) purplish beneath the cinereous 

 pubescence. Length about '2 inches 1U lines (7- millim.). 



The unique example (a female) was obtained at Albany Island in 

 3-4 fms. 



The palpi of the mandibles arc two-jointed ; the joints flattened, 

 dilated, and ciliated, as in Pectus. 



As the specimen is unique, I have not been able to make a com- 

 plete examination of the branchiae; but I think (as in the true 

 l'enai as restricted by Mr. Spence Bate) no true podobranchiae are 

 present, but merely the epipoditic appendages or " mastibranchiae " 

 as he denominates them *. 



There are, besides, in the collection from Port Denison a speci- 

 men closely allied to Pasiphcea and to Leptochela, Stimpson ; and 

 another crustacean, perhaps belonging to the Penaeidea, which, being 

 in very mutilated condition, cannot be described in detail, and 

 which I leave for the present undetermined. 



* Vide Spence Bate " On the Penrcidea," Ann. & Mag. Nat. Hist. ser. 5, viii. 

 p. 174(1881). 



In this recent memoir on the Penseidea several new genera and not a 

 few new species have been very briefly characterized, to none of which, I 

 believe, can our new form be referred. The descriptions, however, are in- 

 sufficient. From HemipeiKBUs, which this species resembles in its short and few- 

 toothed rostrum, it differs in the structure of the flagella of the antennules. 



Mr. Spence Bate includes in the very insufficiently defined genus Pencsopsis the 

 P. styliferus, M. -Edwards, with which he apparently considers P. dobsoni, Miers, 

 to be identical. He has strangely overlooked an important distinction, twice 

 mentioned by me in my paper (vide Proc. Zool. Soc. 1878, pp. 305, 307), 

 namely the absence of lateral marginal spimiles on the terminal postabdominal 

 segment. They are absent, I may add, alike in the female and in Prof. 

 Wood-Mason's small male. The existence of these in P. styliferus is mentioned 

 by Milne-Edwards in his original description of that species, and they are 

 present also in a specimen referred to P. styliferus in the British-Museum 

 collection. 



