272 VERRILL 



The rays are about as long as broad, acute, slightly turned up at 

 tips. It is evidently young. It was preserved in alcohol. 



Dorsal surface reticulated, due mainly to the slender, divergent 

 spinules of the pseudopaxillae. These spinules, which form stellate 

 groups of six to twelve or more on the slender paxillae, are long 

 and thin. Oscular opening small, surrounded by five groups of 

 small spines. 



Adambulacral combs of spines contain four to six, most often 

 five. Of these the inner one is very small ; then three or four much 

 longer, subequal, central ones. Retroambulacral spines longer and 

 larger, horizontally webbed, and partly erect. The horizontal web 

 has a free edge parallel with the ambulacral groove. Peractinal 

 spiracles small, with a narrow valve, free laterally. 



Jaws with five webbed and graded spines, the apical ones much 

 the larger ; lateral ones small and slender. Epioral spines two, large ; 

 distal half nearly transparent; base swollen, white, opaque; tips 

 tapered, slender, acute. 



Ambulacral feet in two rows. 



(?) Puget Sound (Columbia University Expedition). 



This may prove to be the young of P. tesselatus, when specimens 

 of intermediate sizes can be studied. The smallest typical example of 

 the latter known to me is 80 mm. in diameter. They agree in the 

 shortness of the retroambulacral spines, which do not reach the 

 margin of the disk in either case, but end in a raised submarginal 

 web, parallel with the groove. The differences that exist may very 

 likely be due to age and mode of preservation. I see no reason for 

 referring this species to Retaster. The reticulating lines, mentioned 

 by Clark, seem to me to be merely very slender, divergent paxillary 

 spinules, not muscular, nor cartilaginous fibers. Such muscular fibers 

 as were noticed by me were very feeble and irregular. 



PTERASTER MILITARIS (Miiller) Miiller and Troschel. 



Asterias militaris MULLER, Zool. Dan. Prod., p. 234, 1776. Rathke, Zool. Dan., 



iv, p. 14, pi. ex xxi, 1806. 

 Pteraster militaris MULLER and TROSCHEL, Syst. Aster., Suppl., p. 128, pi. vi, 



fig. I, 1842. Stimpson, Invert. Grand Manan, p. 15, 1853. M. Sars, Overs. 



Norges Echinod., p. 48, pi. in, figs. 8, 9, pi. iv, figs. 4-6, 1861. Duncan 



and Sladen, op. cit, p. 46, pi. in, figs. 13-16. Danielssen and Koren, op. 



cit, p, 70, pi. xin, figs. 18, 19, 1884. Verrill, Expl. by the Albatross, p. 



541, pi. xin, fig. 35, 1885 ; Distrib. Echinod., p. 202, 1895. 



Pteraster militaris FISHER, op. cit, 1910, p. 167; op. cit, 191 ib, p. 346, pi. 

 xcvin, figs. I, 2. 



This well-known Arctic and North Atlantic species has been 

 described by Mr. Fisher from several stations off the Pacific coast, 



