230 PROF. BELL ON BATHYBIASTER VEXILLIFER. [A.pr. 7, 



groove. Along the top, the middle and the base of each side, there 

 runs a row of short, sharpish spines ; the upjjermost of them is 

 wanting near the disc and the lowermost fades out near the tip of the 

 arm. 



The arrangement of the paxillfe can be seen from the drawings 

 given herewith ; as there is but a single specimen I have not retnoved 

 the upper plates or injured the type in any way (Plate XXIV. fig. 3). 



There can be little doubt tliat this species has a small anus, and it 

 will be remembered that Sir Wyville Thomson regarded it as an 

 Archaster and notas an Astropecten. The definition of the genus as 

 given by jNiessrs. Korea 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 piuk. 



The single specimen recorded by Thomson was dredged at 

 " Station 7G •' by II. M.S. Porcupine in 18(39 ; Faeroe Channel, GO"* 

 36' N., 3° 9' VV., 344 fms. 



The specific characters may be thus stated : — 



Il=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 

 supeioniarginal 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 " vexiUum," whicli may be an aborted pedicellaria, 

 and the edges of which are finely denticulated. A small anal orifice. 

 Madrej)orite 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 pedicellariie " 

 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 pedicellariee, 

 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 j)laced on an 

 adambulacral spine, and I very much doubt whether that form should 



