OCR Text |
Show 432 PROF. J. A. THOMSON AND MR. W. D. HENDERSON ON [Apr. 10, branches end in short sharp-pointed cones, as seen, for instance, in Leptogorgia australiensis. On the older branches the coenenchyma is thin and shows distinct longitudinal grooves, which can be traced up into some of the twigs where the coenenchyma is much thicker. Under a lens the general texture of the surface is granular. As to the polyps, many show wart-like protruding verruca?, about 0*5 m m . in height, 0*75 in breadth, and 1 m m . in length, the elongation being in the plane of the branch. In many cases, however, the contraction is complete, and only slitlike apertures indicate the position of the polyps. They may occur at any point, but on the main stem and larger branches they tend to be lateral. The transparent pale yellow spicules of the coenenchyma are warty spindles, while some approach a club-shaped form. They have the following measurements, length by breadth, in millims. :- (a) Spindles with warts in whorls: 0*18x0*04; 0*16x0*05; 0*18x0*05; 0*2x0*04. (b) Spindles with irregularly-placed warts: 0*16x0*06; 0*18 X0-05; 0*18x0*06. (c) Small irregularly-warted spindles : 0*08 X 0*04 ; 0*1 X 0*04 ; 0*09x0*045. Locality. Cape Verde Islands. LOPHOGORGIA CRISTA Mobius. (Plate XXIX. figs. 5-7.) Two plume-like brownish-red colonies resemble Lophogorgia crista Mobius in the following features :-(1) the general habit of the colony; (2) the flattening of the larger branches in the plane of ramification; (3) the nature and thickness of the coenenchyma ; (4) the hint of striations; and (5) the spiculation near the base. The two colonies measure 34 and 35 centims. in length, 6 and 10 centimsj. in breadth; the basal (broken) ends 7 and 6 m m . in one diameter and 3*25 and 3*4 m m . in the other. The spicules from the lower end of the colony are warty spindles, with the warts in 2-4 whorls. They are beautifully coloured, with the spindle-core red and the projecting warts of a pale translucent yellow. The following measurements were taken (in millims.):- (a) Of spindles with two whorls of warts: 0*09x0*05; 0*1 x 0*06. (b) Of spindles with three whorls of warts: 0*09 X 0*05; 0*1x0*06. (c) Of spindles with four whorls of warts: 0*1x0*04; 0*12x 0*06. Spicules taken from the tips of the branches are slightly different from those at the base. Many of them are longer, more slender spindles with up to 10 whorls of warts. The following measurements were taken of length and breadth in millims. :-0*18x0*04 ; 0*19x0*04; 0*16x0-06; 0*13x0*06. The majority are coloured like those at the base, but there are also some wholly yellow forms with warts either regularly or irregularly disposed. |