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Show 100 MR. F. E. BEDDARD ON ISOPODA COLLECTED [Feb. 2, the thoracic appendages are slender and not greatly elongated ; they terminate in a single claw ; the first pair are subcheliform. The uropoda are rudimentary, consisting of only a single conical setose joint. 1. ASTRURUS CRUCICAUDA, n. Sp. This species is represented by a large number of individuals dredged in shallow water off Kerguelen ; the largest individuals only measure 4 or 5 millim. in length. The body is more or less pear-shaped, the anterior region of the thorax being wider than the posterior. The head is narrower than the succeeding segment of the thorax ; it is prolonged anteriorly into two long slightly divergent processes, each of which is as long as the head itself; laterally is a longish process on either side, which terminates in a slightly swollen extremity ; these processes resemble the eye-stalks in Munna, and they contained some orange-coloured pigment in the interior, but no recognizable trace of lenses ; the surface, moreover, is covered with numerous short spines like the rest of the body. The four anterior thoracic segments are of nearly equal length, but they increase in width up to the third ; the median region of these segments is convex and densely covered with short spines; the lateral margins are prolonged into long stout spines, which are themselves covered with short spines like the thoracic segments and the rest of the body. The three posterior segments are all much shorter than the fourth segment, and decrease gradually in length ; their lateral margins are without the greatly elongated spines of the anterior segments ; only on the fifth and sixth segments one of the spines which fringe the body is rather more elongated than the rest. The abdominal shield is oval, tapering posteriorly; it terminates in four somewhat flattened spines arranged in the form of a cross. The antennules consist of a two-jointed peduncle and a five-or six-jointed flagellum ; the proximal joint of the peduncle is broader and shorter than the succeeding joint. The antennae are not so long as the body but considerably longer than the antennules ; the two proximal joints of the peduncle are elongated, the flagellum is shorter than either of these. The mandibles have a three-jointed palp. The first pair of thoracic appendages are modified into a prehensile limb; the remaining thoracic appendages are slender and elongated, particularly the three posterior pairs. The uropoda are rudimentary as in Munna. Kerguelen, 120 fathoms. NEASELLUS, F. E. B. Neosellus, F. E. Beddard, Narr. Chall. Exp. vol. i. p. 882. fig. 326. This new genus is represented by a single species from Kerguelen. It comes near to Pleurogonium and Leptaspidia, but is distinguished by the great horizontal elongation of the head, which is as wide as the following segment and bears the antennary organs at the |
