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Show 98 ZOOLOGICAL COLLECTIONS MADE DURING [Jan. 4, The madreporic plate is obscured by the paxillse, which are nowhere arranged in regular rows. The interpaxillar area is 8 millims. wide at the base of the arm, and 1 millim. at the apex ; the total width of the arm at the base is 15"5 millims., and at the tip 2*2 millims. OPHIUROIDE A. OPHIURIDA. OPHIACTIS ASPERULA. Ophiolepis asperula, Philippi, Archiv fur Naturg. (1858), p. 267. Ophiactis asperula, Liitken, Addit. ad Hist. Oph. ii. (1859), p. 130, footnote. Ophiactis magellanica, Ljungman, Vetensk. Akad. Forh. 1866, p. 164. Ophiactis asperula, Lyman, Bull. C. M . Z. vi. 2, p. 41. (1) Port Rosario, 2-30 fms. ; bottom, sand and rock. (2) Tom Bay, 0-30 fms.; bottom, rock, kelp, and mud. (3) Elizabeth Island, 6 fms.; sandy bottom. (4) Sandy Point, 9-10 fms.; bottom, mud. (5) Borja Bay, 14 fms.; bottom, shell and stones. OPHIOSCOLEX COPPINGERI, sp. n. (Plate VIII. fig. 6.) This species is to be at once distinguished by the irregular distribution of the uppermost row of arm-spines, which are, though not regularly, set almost alternately in an upper and a lower plane. The disk is rounded in the larger, subpentagonal in the smaller specimen. Arms long, slender, delicately tapering, widest at the base, with three lateral arm-spines, of which the uppermost, which is a little the longest and of about the same length as an arm-joint, is not always placed at the same level, but is not unfrequently higher up or lower down on the side of the arm than is the corresponding spine of the next joint. The three or four outer mouth-papillae are short and spinous ; the most central is broadened out and pectinate at its margin, closely resembling the teeth, of which there are at least three in each jaw. The buccal shield is only visible when the skin is removed, is somewhat ovoid, with the narrower end internal. There is a deep notch on the upperside of each arm-joint, so that the dorsal plates are only near one another in the middle line, but the calcareous plates do not here even touch one another ; along the upper median line there runs a well-marked groove, an indication of which, as passing all along the arm, can be made out even before the skin is removed ; the lower arm-plates are regular and oblong. Genital slits rather long. The following are the more important measurements of the largest specimen :-Diameter of disk 2 0 5 millims. ; length (longest) arm 80 millims. ; breadth of arm (at base) 3 millims. ; length of genital slit 4 millims. Three specimens, one with the disk injured, were collected at Tom Bay, 0-30 fms.; bottom, rock, kelp, and mud. |
