64 ASTEROIDEA. 
PORCELLANASTERID& (see p. 20). 
CTENODISCINA (see p. 20). 
CTENODISCUS. 
Ctenodiscus, M. 77. Syst. Ast. (1842) p.76; Perr. Arch. Zool. expér. iv. 
(1875) p. 802; Vag. op. cit. vii. (1878) p. 226. 
With the characters of the subfamily. 
1. Ctenodiscus crispatus. (Plate X. figs. 1-3.) 
Asterias crispata, Retz, Diss. Spec. Ast. (1805) p. 17. 
Asterias polaris, Sabine, Suppl. to Appendix of Parry’s Voyage, 
(1824) p. cexxiil, pl. i. figs. 2 & 3. 
Astropecten polaris, Gray, Ann. &§ Mag. vi. (1840) p. 180. 
ee enger polaris, M. Tr. Syst. Ast. (1846) pp. 76 & 129, pl. v. 
g.0. 
Ctenodiscus pygmeus, td. op, cit. p. 76. 
Ctenodiscus crispatus, Dib. § Kor. Vet.-Akad. Hdlg. 1844 (1846), 
» p. 253; Sars, Nyt Mag. vi. (1851) p. 160; Stimpson, Inv. Grand 
Manan, (1855) p. 15 ; Liitken, Vid. Medd. 1857, p. 45; Sars, Norg. 
Ech. (1861) p. 26; Verrill, Proc. Bost. Soc. N. H. x. (1866) 
pp. 845 & 856; Perrier, Ann. Sct. Nat. xii. (1869) p. 298; Stua- 
berg, difv. Vet.-Akad. Forh. xxxv. (1879) no. 3, p. 30; Jarzynsky, 
Cat. Ech. rn mari albo apud Wagner, Wirbellos. Weiss. Meer. 
(1885) p. 170. 
Ctenodiscus corniculatus, Perrier, Arch. Zool. expér. v. (1875) p. 300 ; 
Viguier, Arch. Zool. expér. vii. (1878) p. 228; Duncan § Sladen, 
Greenl. Ech. (1881) p. 49; Koren § Danielssen, Norske Nordhavs 
Ast. (1884) p. 84; Sladen, Chall. Rep. Ast. (1889) p. 171. 
R= air 
General form stellate, with rather deeply incurved sides, flat- 
tened; a large terminal plate. Ambulacra wide, with large suckers, 
and bordered by a row of spines, three to each plate, and externally 
to them one or two others, which are generally rather smaller. The 
ventral surface spineless. The marginals with spines ; the supero- 
marginals are elongated from above downwards and form a vertical 
wall on every side of the disk; neither on them nor on the infero- 
marginals is a spine always developed, but it is generally; it is 
never large, and there is never more than one. ‘There are about 
fifteen marginals on either side of each arm. The paxilliform 
plates of the upper surface are very delicately stellate and closely 
packed. The madreporite, which is distinct and rather deeply 
grooved, is not far from the margin of the disk. 
Coleur in spirit creamy yellow. 
R. T. 
28°5 14 
26 14 
24 Lt 
