OCR Text |
Show 1877.] CRUSTACEA, CHIEFLY FROM SOUTH AMERICA. 661 but little longer than the wrist; fingers slender, without strong teeth on their inner margins ; the sides of the carapace, below the lateral hepatic spine, are nearly smooth. The third and smallest specimen (length to tip of rostrum 1 inch 5 lines) differs from the preceding in having thirteen teeth on the upper margin of the rostrum, the three apical teeth being somewhat smaller and more crowded, as in P. montezumee, Saussure, from the Gulf of Mexico ; the wrist of the second pair of legs is not, however, shorter than the palm, as in that species. This I regard merely as a variety of P. brasiliensis. Although it may be well, in the present state of our knowledge, to maintain P. nattereri and P. brasiliensis as distinct species, the differences existing between them are very slight, scarcely sufficient for specific distinction, if regard be had to the identity of locality and the variations that are known to exist in individuals of a single species. This and the preceding species are omitted by Smith in his list of the known species of Brazilian Decapoda (Trans. Conn. Acad. ii. p. 40, 1870). PAL.EMON JELSKII, sp. n. (Plate LXVII. fig. 1.) Slender, smooth, with the lateral margins of the segments of the abdomen straight. Rostrum very long and slender, reaching beyond the end of the basal scale of the external antennse, at base rising considerably above the dorsal surface of the carapace, apex slightly directed upward ; upper margin with 6-7 teeth towards the base, and three small and crowded at apex, lower margin with 7 teeth. Eyes large. Antennules with the peduncles reaching considerably beyond their basal scales, but not to the extremity of the basal scale of the antennse ; longest flagella very slender, about as long as the animal; antennse with the peduncles short, not reaching halfway to extremity of basal scale ; flagella extremely long and slender, longer than the animal. Second pair of legs filiform, no thicker than the rest, and not much longer than the carapace and rostrum ; wrist very long and slender, about twice as long as the hand, which has the palm and fingers equal, fingers hairy. Length about 1 inch 8 lines. Hab. Guiana (Oyapok) (Jelski). This species is evidently very nearly allied to P. amazonicus, Heller, Sitzungsb. /. c. p. 418, pl. ii. fig. 4, 5 (1862) ; but it differs in the fewer teeth upon the lower margin of the rostrum, which is less raised at the extremity, and the far longer wrist of the second pair of legs. In the form of the rostrum it slightly resembles Palcemon ensiculus, Smith, Trans. Connect. Acad. ii. p. 26, pl. i. fig. 2 (1869), but differs in the number of the teeth and in the form and proportion of the joints of the second pair of legs. Two specimens are in the collection. PALCEMON GAUDICHAUDII. Palcemon gaudichaudii, M.-Edwards, Hist. Nat. Crust, ii. p. 400 |