ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS FISHER. 31 



As mentioned under the generic description it seems better to place this 

 species under Eremicaster than with Porcellanaster, tlie segmental papilltB being 

 subject to indivitlual variation, while so far as known there is no variation in the 

 number of cribriform organs. 



Subfamily CTKNODISCINyK Sladen. 1889. 



"Porcellanasteridfe with a simplified form of cribriform organ on the margins 

 of each pair of marginal plates. Actinal interradial areas traversed by fimbriated 

 channels, in continuation of the fasciolar or cribriform channels between the marginal 

 plates" (Sladen). Superambulacral plates present, though not well developed. 



Genus CTENODISCUS Mullen and Troschel. 



CUnodiscus Muller and Troschel, System der Aeteriden, 1842, p. 76. Type, Asterias polaris 



Sabine=A. crispata Retzius. 

 Anodisms Perkier, Ann. sci. nat., s4r. 5, vol. 12, 1869, p. 298. 



Diagnosis. — General form stellato-pentagonal to stellate; abactinal surface 

 with true pa.xillae: marginal plates thicker than in tj-pical Porcellanasteridtc; mar- 

 ginal, actinal intermediate, and adambulacral plates obscured by a continuous 

 skin; marginals bearing each a short spine at upper end of plate, these forming two 

 longitudinal series along ray; cribriform organs in the form of fasciolar grooves 

 between marginal plates, these grooves continued as simple channels (roofed by 

 webbed spinelets) across actinal intermediate area and between adambulacral 

 plates; adambulacral plates with three to five furrow spinelets. No anus. Super- 

 ambulacral plates present. 



CTENODISCUS CRISPATUS (Retzius). 

 PI. 3, figs. 1-4: pi. 4, figs. 1-6. 



Asterias ens pata Retziu.s, Dissert, sistena species cognitas Asterianim, 1805, p. 17. 



Ctenodiscus crispatus Duben and Koren, K. Vetensk. Akad. Handl., 1844 (1846), p. 253. 



Cienodiscits au^tralis (Lov6n MS.) LiJTKEN, Vid. Medd., 1871, p. 238. 



Ctenodiscus krausei Ludwig, Echinodermen des Beringsmeeres, Zool. Jahrb., Syst., vol. 1, 1886, 

 p. 293. 



Ctenodiscus procurator Sl.\den, Challenger Asteroidea, 1889, p. 173, pi. 30, figs. 7-12. For numer- 

 ous citations to 1899 see Ludwig, Fauna Arctica (Ronier and Schaudinn, Jena) 1900. p. 4.50; 

 also, Mem. Mus. Comp. Zool. vol. 32, 190.5, p. 104, pi. 6, figs. 32, 33, for record in equatorial 

 east Pacific. 



Diagnosis. — Rays five, exceptionally foiu- or sLx. R = 1.66 r to 3.16 r. General 

 form stellato-pentagonal, to stellate, extremely variable. Abactinal surface more or 

 less tumid and usually with an elevated cone in center of disk; paxilhe variable, 

 usually low, with few to many spinelets which are short, clavate, and skin-coveretl. 

 Marginal, actinal intermediate, and adambulacral plates obscured by a thin soft 

 skin. Continuous narrow deep grooves extend between marginal plates, across 

 intermediate area, and between consecutive adambulacral plates. These are 

 overhung on either side by a fold of skin embedded in which arc numerous 

 flattened spinelets, as in the lamellte of typical cribriform organs. Between special 

 raised ridges of marginal plates these furrows are deeper and V-shaped with five to 



