116 OPHIUROIDEA. 



20th arm-joint. Arm-spines 7-9, very short, and quite insignificant. 

 Colour in spirit yellowish white. 



Pound by 'Porcupine ' at St. 45 a (51° 1' N., 10° 2' W.), 180 fms. ; 

 specimens apparently lost. 



Distribution. North and South Atlantic, N. and S. Pacific (with 

 some variations, fide Lyman). 180 to 1825 fms. 



2. OPHIOCNIDA. 



Ophiocnida, Lyman, III. Cat. 31. C. Z. i. (1865) p. 133; id. Chall, Ben. 



,Oph. (1882) p. 152. 

 Ophiocoma, Forbes, Brit. Star/. 1840, p. 30 (pars). 

 Ophiolepis, M. Tr. Syst. Ast.'(1842) p. 89 (pars). 



No tooth-papillae ; teeth ; mouth-papillae not numerous. Disk 

 small, with naked radial shields and fine scales ; arms long and 

 slender ; arm-spines short, stout and solid. Plates of disk spiny or 

 granular. 



1. Ophiocnida brachiata. (Plate XIII. figs. 3-5.) 



Asterias brachiata, Montayu, Trans. Linn. Soc. vii. (1804) p. 84. 

 Opbiura brachiata, Leach, Zool. Misc. ii. (1815) p. 57 ; Flem. Brit. 



An. (1828) p. 488. 

 Opbiocoma brachiata, Forbes, Brit. Star/. (1840) p. 45 ; Thompson, 



Nat, Hist. Irel. iv. (1856) p. 437. 

 Ophiolepis (Ophiopholis) brachiata, M. Tr. Syst. Ast. (1842) p. 96. 

 Ophiopholis brachiata, Gray, Cat. Brit. Bad. (1848) p. 25. 

 Amphiura neapolitana, Sars, Nyt May. x. (1859) p. 35 (pi. i. 



tigs. 11-15). 

 Ophiocnida brachiata, Lyman, Cat. Mus. C. Z. i. (1865) p. 12; 



Ljunyman, (Efv. Vet.-Akad. Forh. 1866 (1867), p. 317 ; Fischer, 



Actes Soc. Bord, xxvii. (1869) p. 362 ; Ljunqman, (Efv. Vet.-Akad. 



Forh. 1871 (1872), p. 642 ; Ludwiy, Mitth, zool. Stat. Neap. i. 



(1879) p. 550; Lyman, Chall. Rep. Oph. (1882) p. 155; Leslie § 



Herdman, Proc. B. Phys. Soc. vi. (1881) p. 89 ; Jloi/le, op. cit. viii. 



(1885) p. 145; Cams, Faun. Med. (1884) p. 95. 

 Ophiocnida neapolitana, Lyman, Cat. Mas. C. Z. i. (1865) p. 137. 

 Amphiura brachiata, Norm. Ann. cy May. xv. (1865) p. 109. 



Arms fifteen to twenty times as long as the radius of the disk. 

 Disk pentangular ; covering-scales small, closely packed, imbricating, 

 with a free edge near the periphery and forming at it spinous 

 processes. Eadial shields small, triangular. The very long arms 

 have about eight flattened short spines ; upper arm-plates nearly 

 twice as broad as long, lower nearly square ; two tentacle-scales at 

 base of arm, and one elsewhere. 



P = 110 (about); r = 6-5. 

 R = 100 (about) ; r == 6. 



The arms are often a good deal twisted or curved. 

 Colour, dry, various shades of yellow or grey ; " when alive 

 purplish brown and sometimes bluish ash-colour " (Montagu). 



