OCR Text |
Show 1881.] THE SURVEY OF H.M.S. 'ALERT.' 51 projecting into them from the side, giving them more or less of a crescentic appearance. One specimen, which was taken from the base of a Sponge and grew partially over an Idmonea, was bent over on itself, so that the two halves appeared inclined to unite back to back and form an Escharoid frond; but there was a space between them, which was perhaps originally partially filled with the substance of the Sponge. Hab. Elizabeth Island, 6 fathoms; Sandy Point, 7-10 fathoms; on flexible worm-tube and Balanus sessile on the same. Also T o m Bay, near Madre de Dios archipelago, 0-30 fathoms, on base of Sponge. Obs. The different specimens vary much in the distinctness of the cells and the number and regularity of the punctures. LEPRALIA APPRESSA, Busk, var. nov. VINOSA. (Plate VI. fig. 4.) Lepraliapertusa, Manzoni ? Sitzungsb. A k . Wien, lix. (2) p. 520, pi. ii. fig. 11 (Pliocene). Lepralia adpressa, Busk, Cat. Polyz. Brit. Mus. p. 82, pi. cii. figs. 3, 4, pi. ii. fig. 11. Zocecia distinct, moderately to broadly ovate, or obscurely pentagonal, slightly convex, closely adnate to surface as a compact zoarium. Mouth defined by a slightly salient narrow rim, well arched above, constricted towards lower angles by two rounded processes projecting into the aperture; lower lip entire, somewhat irregular in outline, slightly projecting outwards. Surface of zocecium covered with obscure tubercles, arranged in a series round edge of cell and over the surface, sometimes in transverse series across the cell ; surface granular. Colour of zocecia, with the exception of the rim of the mouth (which is white or brownish) and the apices of the tubercles (which appear white), puce (or crimson-purple) ; colour faint on oldest parts of zoarium. Ooecium small, slightly convex, minutely roughened, not tuberculated, subcircular, brownish. Hab. Portland Bay, S.W. Chili, 10 fathoms, on shell of Crepipa-tella. Obs. This species resembles L. lata, Busk., and L. adpressa, Busk (lately united by Hincks, in Hist. Brit. Mar. Polyzoa, under the latter name), so closely in all essential characters except the colour, that I have hesitated to give it a new appellation. However, as compared with the type specimen of L. adpressa and the figures of L. lata, the aperture of the mouth is seen to be much less clearly defined, the lower lip being very indistinct, and the mouth is considerably smaller. These characters m a y be due to thickening of the wall to some extent; but still the colour remains. But as Lepralia {Microporella, Hincks) violacea, Johnst., may vary from dark purple to cream-colour, and Lepralia {Mucronella, Hincks) coccinea, Abild., with a<*e from grey to red, it appears not safe to depend on this alone as a specific character. It is noteworthy that it adheres to the practice of its allies, of growing on a shell. 4* |