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Show 230 PROF. BELL ON BATHYBIASTER VEXILLIFER. [Apr. 7, groove. Along the top, the middle and the base of each side, there runs a row of short, sharpish spines ; the uppermost of them is wanting near the disc and the lowermost fades out near the tip of the arm. The arrangement of the paxillte can be seen from the drawings given herewith; as there is but a single specimen I have not removed the upper plates or injured the type in any way (Plate XXIV. fig. 3). There can be little doubt that this species has a small anus, and it will be remembered that Sir Wyville Thomson regarded it as an Archaster and not as an Astropecten. The definition of the genus as given by Messrs. Koren and Danielssen must be so far modified as to run "Anus present or absent " (cf. Plate XXIV. fig. 6). The colour of the dried specimen is light yellow ; Thomson states that during life it is of a pale rose, with a tinge of buff, the suckers semi-transparent and pale pink. The single specimen recorded by Thomson was dredged at " Station 76 " by H.M.S. Porcupine in 1869 ; Faeroe Channel, 60° 36' N., 3° 9' W., 344 fms. The specific characters may be thus stated : - R=5r. Arms and disc flat, the former with deep vertical sides formed by the marginals, of which there are about 70 in each row ; those of the supermarginal series have each a single short spine near the upper edge, and the inferomarginal similar and subequal spines near the upper and lower edges. The adambulacral spines are arranged by fours on two sides of a triangular plate, the apex of which looks into the furrow and bears a spine. Connected with this spine is a grooved spiniform body or " vexillum," which may be an aborted pedicellaria, and the edges of which are finely denticulated. A small anal orifice. Madreporite small, near margin of disc. Generic Affinities.-The general characters of this form obviously ally it to Bathybiaster, as Messrs. Koren and Danielssen suggested, but it appears to be necessary to make some modifications of the original generic diagnosis. The first statement is that the body is flat; to this B. loripes var. obesa is an exception. The next is " 5-rayed, with an extremely wide ambulacral furrow, having long pedunculated, peculiar pedicellarise along its margins." I am inclined to suggest that the expression " peculiar pedicellarhe " might be replaced by the indifferent term " vexillum." Owing to the dried condition of Thomson's specimen, I cannot make any addition to or critical remark on the descriptions of previous writers, but it will be remembered that the learned Norwegian natuialists recognize the great differences between these appendages and normal pedicellarise, and that Thomson says no more than that they may be " abortive pedicellarise." In Mr. Sladen's species the structures at the sides of the ambulacral grooves are not pedunculate pedicellarise placed on an adambulacral spine, and I very much doubt whether that form should |