OCR Text |
Show 60 ZOOLOGICAL COLLECTIONS MADE DURING [Jail. 4, Hab. Elizabeth Island, Straits of Magellan, 6 fathoms, on Fucus. . Three colonies or parts of colonies. Obs. In some specimens the regularity of the arrangement of the cells in transverse rows and the length of the free portion of the cells is greater than in others. The most characteristic points appear to be the moderate expansion of the head of the lobes, the continuation of the transverse series of cells over the top of the ridge and consequent absence of a median bare line, and the distinctness of the cells in the rows. D'Orbigny's figures represent the form with the shorter cells and less regular transverse series of cells; the alternative form here described may be called var. serialis in contrast. A specimen assigned with doubt to this species consists of a broad expanded lobe, and bears a flattened trumpet-shaped ocecial orifice having exactly the characters of'that described above in T. organizans, d'Orbigny. ENDOPROCTA. P E D I C E L L I N A AUSTRALIS, sp. n. (Plate VI. fig. 8.) Individuals arranged with great regularity along the creeping stolon, P8 millim. apart from each other. Length of pedicel and body together about 2"5 millims., body 1 millim. Tentacles about 12 in number, subequal, length about half that of body, slender. Pedicel, diameter (in glycerine, under cover-glass) just above base -35 millim., tapering to about '25 when within 3 diameters of the body, ultimately constricted to '1 millim. at junction with body. Body subtransparent. Colour whitish, with the exception of the stomach, which is yellowish. Shape of body subglobular when closed, superior margin straight and crenated by about 60 small inequalities. Stolon regular in its diameter, viz. "17 millim. A transverse septum, of which, as in the case of that of the pedicel just below the body, the cuticle forms a part, occurs at each side of the point of origin of an individual, generally at about -5 millim. from this. Examined. In spirit and in glycerine. Hab. Sandy Point, in company with a Halecium, creeping over large flexible worm-tube, 7-10 fathoms. Obs. About a square inch or 1| inch of the tube is covered by the creeping stolon ; the specimens are very well preserved in spirit; but, unfortunately, the individuals are all more or less closed. In the cases in which the tentacles were extended, the disk was not expanded ; so that the origin of the tentacles from it was not clearly seen. It is perhaps most closely allied to P. americana, Leidy, but approaches most nearly to P. belgica, Van Beneden, of any of the European species, as far as the account of that species goes. It differs from the latter species in the proportional length of the tentacles to the body, which is only about 1 :2, as against the almost J : 1 of that species; in the proportional shortness of the pedicel to the body, which is 1*5 millim. to 1 millim. against 2-85 millims. to •55 millim., which is the case in P. belgica. The individuals are 1*8 millim. from each other, arranged along the tubular stolon, and not |