OCR Text |
Show 1881.J THE SURVEY OF H.M.S. ' ALKRT.' 129 species. The skeleton, however, is less regularly rectangular; and the primary fibres appear to project but little. VIOA CARTERI, sp. ii. (Plate XI. fig. 2.) Sponge composed of irregularly ramifying vesicular masses, lining similarly shaped perforations in solid bodies. Body-wall and membranes thin, carrying felted or fasciculated aggregations of the skeleton-spicule. Vents scattered, papillary. Colour (in spirit) vivid crimson. Skeleton-spicule smooth, stout, spinulate, slightly curved, tapering to point; head spherical, exceeding the body in diameter ; length '394 millim., breadth of body '0152 millim. Flesh-spicules scattered, numerous, spiro-spinular (i. e. elongated, spiral, spined), the curves deep, alternately angular and convex; spines long and slender; length '0412 millim.", breadth (without spines) '00127 millim. Examined. In spirit, and by mounting in balsam. Llab. Victoria Bank, offS. Brazil, lat. 20°42'S., long. 37°27'W., calcareous rock, nullipore (?) &c.; bottom, dead coral; 39 fathoms. One specimen (or possibly more in the single mass of rock) represents this species in the collection, spreading in the interior of a flatfish, irregularly exca%rated, calcareous mass, and appearing in section at the broken edge of the mass, as well as indicating its presence by its various vents scattered over the surface; at these points a dark-crimson central spot is seen, surrounded by a fainter colour, apparently the result of the staining of the surrounding rock by the Sponge. External Form and Characters. To the above may be added that it forms botryoidal irregular deep-lying masses, which ramify irregularly to the exterior, by sending out long narrowing tubes which end on the surface in the vents. Obs. The coloration of this sponge is exactly the same as that of dry specimens of Vioajohnstoni, Schmidt, or, rather, of the form wrongly described under that name in 1870 by Schmidt (Atl. Geb. p. 5, pi. vi. fig. 18), in which sponge, as in this, the tint is not permanently altered by the action of potash; it is almost identical with that of a reputed specimen of Alcyonium purpureum, Lamk., in the national collection referred to by Mr. Carter (Ann. & Mag. N. H. [4] xvi. p. 197). The generic name Vioa, put forth in 1833 by Nardo (Isis, 1833, p. 523), for a genus said to be founded on "Alcyonium asbestinum, Linn.," and adopted by Schmidt (Spong. adr. Meer.), is here used in preference to Cliona, published in 1826 by Grant (Edin. N e w Philos. Journ. i. p. 79); for this name, under the form Clione, was already occupied, having been applied in 1774 by Pallas (Spicilegia Zool. fasc. x. p. 28) to a genus of Pteropodous Mollusca. By the specific name the Sponge is dedicated to Mr. H. J. Carter, whose work in this difficult genus has done so much to elucidate its anatomy and determine its systematic position, and to whose assistance in m y work among the British-Museum sponges I am so much indebted, PROC. ZOOL. Soc-1881, No. IX. 9 |