OCR Text |
Show 300 MR. E. J. MIERS ON THE PEN.EID.E. [Mar. 5, P. semisulcatus, there is a short dorsal carina which does not reach to the posterior margin of the cephalothorax and is not canaliculated above, and the gastro-hepatic sulcus is very deep and strongly defined. For this latter form I propose to retain Fabricius's name of P. monodon, if the two species be distinct; as it would seem that the common Indian form must be designated by De Haan's name of P. semisulcatus, it having been first distinctly characterized by him, while it is impossible to ascertain from Fabricius's brief description which of the two species was known to that author. The figure of P. tahitensis of Heller (Reise der Novara, Crust. p. 121, pl. xi. fig. 2, 1865) resembles this species ; and in it the rostrum is represented as 3-toothed below; but it is described as edentate ; so I cannot refer it with certainty to P. semisulcatus. The P. carinatus of Dana (U.S. Expl. Exp. xiii., Crust, i. p. 602, pl. xl. fig. 2, 1852), from Singapore, is only briefly described, but appears to be identical with P. semisulcatus, with which it agrees in the form and number of the teeth on the rostrum. It is not, however, mentioned in the description whether the longitudinal carina on the cephalothorax is sulcate or not. PENEEUS HARDWICKII, sp. n. (Plate XVII. fig. I.) The cephalothorax is very minutely granulated ; tbe cervical suture is in its posterior half, and the cardiaco-branchial altogether, obsolete; a canaliculated dorsal crest extends from the base of the rostrum to the posterior margin. The rostrum reaches beyond the peduncles of the antennules, is 8-9-dentate above, the last tooth separated by twice the ordinary distance from the preceding; the inferior margin is entire; it is curved regularly upward toward the distal extremity, which is acute. There is a spine on the underside of the second joint of the first and second pairs of legs, and none on the third pair. The form of the sternum is as in the P. curviros-tris of Stimpson ; and the third to sixth postabdominal segments are carinate as in that species. Tbe last postabdominal segment is deeply longitudinally sulcate above, and, as in P. semisulcatus, acute at apex, without lateral spines. Hab. Indiau Seas 1 (Hardwicke). There are two specimens in the British-Museum collection, of which the exact locality is not known. This species is most nearly allied to P. curvirostris, Stimpson, from Simoda, Japan, but differs in having a canaliculated dorsal crest, and a longer rostrum, which is acute at the extremity ; the sutures of the cephalothorax are also much less distinct. From the P. semisulcatus of De Haan, which resembles this species in having a single longitudinal dorsal sulcus, it differs in the form of the rostrum, which is edentate below, and in having only a single spine at the base of the first pair of legs,- and from the P. sculptilis of Heller, from Java, another unisul-cate species, in the longer, more curved rostrum, and in the postabdomen being keeled only on the third to sixth segments, whereas in P. sculpttilis all the postabdominal segments are said to be keeled. |