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Show 922 MR. F. E. BEDDARD ON ISOPODA COLLECTED [Dec. 1, unfortunately only represented by a fragment, dredged near the Antarctic ice-barrier from a depth of 1950 fathoms. The head and the first four segments of the thorax (all that is left of the specimen) are subequal in length ; each of the four thoracic segments is furnished with a long slender spine in the dorsal median line ; the last three segments have in addition a pair of more laterally placed spines, which are absent from the first segment of the thorax but present upon the head, and situated a little way behind the articulation of the antennae. On the epimera were also two or three long spines. The ventral side of the body is comparatively smooth ; each of the segments, however, has a minute median spine nothing to compare with those on the dorsal surface, which equal or exceed in length the diameter of the body. Station 157, 1950 fathoms. ACANTHOCOPE, nov. gen. Two individuals, apparently representing as many species of a Munnopsid from the southern hemisphere, I regard as the type of a new genus. The characters of the genus may be stated in the following words : - General form of the body oval; no marked difference in breadth between the anterior and posterior regions of the thorax. Anterior segments of the thorax increase progressively in length ; the posterior segments of thorax subequal ; epimera of all the thoracic segments from the second onwards enormously elongated into curved sickle-shaped spines. The abdominal segment is oval, with a long terminal spine nearly twice its own length and two pairs of lateral spines, one more anterior, the second overlying the articulation of the uropoda; from the inferior surface of the abdominal segment, beneath the articulation of the latter, arises another pair of long spines. Antennae with the two basal joints short, and furnished with one or two long lateral spines. Mandihles divided into several tooth-like processes ; molar process stout and powerful, with a blunt edge suitable for crushing ; palp small and three-jointed. First two pairs or first pair only of legs shorter and more slender than the rest, the two or three following pairs subequal and not greatly elongated. Posterior thoracic appendages natatory. Uropoda long, styliform, 3- or 5-jointed. 1. ACANTHOCOPE SPINICAUDA, n. sp. A single male specimen was dredged between Kerguelen and Australia at a depth of 1800 fathoms. It measures about 7 millim. in length, inclusive of the telson spine. The general form of the body is oval; the first four segments of the thorax are short, gradually increasing in length up to the fourth ; the three posterior segments are together twice as long as the four anterior; all the thoracic segments, with the exception of the first, are furnished with long spiniform epimera ; on the first four thoracic |