58 



CEINOIDEA. 



xii. (1884) p. 362; Verrill, Ann. Rep. Comm. Fish. 1882 (1884), 

 p. 661 ; P. II. Carp. JBijd. Dierk. 13. vi. (1886) p. 9. 

 Antedon tenella, P. H. Carpenter, Chall. Rep. (1888) p. 169 ; id, 

 Journ. Linn. Soc. xxiv. (1891) p. 58, pi. ii. figs. 5-8. 



A -. 

 ab 



Allied to the foregoing, but distinguished by the smaller number 

 of cirrus-joints and the obscureness of the radials. Cirri numerous, 

 as many as eighty, with less or more than twenty joints, some of 

 the more proximal of which are greatly elongated, while some of 

 the more distal carry spines. The free surface of the centrodorsal 

 rounded or conical ; it does not completely obscure the first radials, 

 but the second is nearly hidden by the large backwardly projecting 

 axillary, which is ordinarily wider than long, and whose distal 

 angle nearly or quite separates the first brachials from any contact 

 with one another ; the second brachial has a very sharp backwardly 

 directed angle, and the third is a syzygy. The four next are alter- 

 nately very wide on one side and narrow on the other ; a syzygy on 

 the eighth, twelfth, and then after each two joints. The joints 

 triangular, then more or less quadrate. The first pinnules long, of 

 about forty joints ; the next very much shorter, with only a few 

 joints. 



Exhibits a considerable amount of variation. 



Colour in spirit white. 



This is a small species with arms less than 50 mm. long., with 

 the longest cirrus about 25 mm., and the first pinnule 15 mm. long. 



Distribution. Both sides of ]S T orth Atlantic, and Arctic Ocean 

 (Kara Sea). 50-740 fms. 



60° 11' 25" N., 8° 15' W., or | QQK ,«,„ , erv .. , _, ,_ rN 



60° 20' 15" N., 8° 8' W., | 28o ~ 433 lms - Triton ' Exp. (St. 5). 



b. 60° 6' N., 8° 14' W., 440 fms. < Porcupine ' Exp. (St. 51) 



c. 59° 56' N., 6° 27' W., 323 fms. < Porcupine ' Exp. (St. 54). 



5. Antedon prolixa. 



Antedon prolixa, Sladen, in Duncan $ Slad. Echin. Greenland, (1881) 



p. 77, pi. vi. figs. 7-10 ; P. H. Carpenter, Bijdr. tot de Dierk. xiv. 



(1887) p. 44, figs. 2 & 3; id. Journ. Linn. Soc. xxiv. (1891) p. 55, 



pi. ii. figs. 1-4. 

 Antedon sarsii, v. Marenzeller, Denk. Ah. Wien, xxxv. (1878) p. 381 . 

 Antedon hystrix, P. H. Carp. Proc. Roy. Soc. Edin. xii. 1 1884) 



p. 365 ; id. Chall. Rep. (1888) p. 165. 

 Antedon celtica, Nansen, Myzostomernes Anat. (1885) p. 6. 

 Antedon quadrata, Fischer, Die bsterreich. Polar-Station Jan Mai/en. 



iii. (1886) p. 31. 



This species has given rise to a good deal of confusion, which 

 Carpenter (J. L. S. xxiv. I.e.) has attempted to unravel. He 

 does not, however, give a definite diagnosis, but rather indicates 

 why it is to be distinguished from A. tenella, Eetzius. 



