1913.] Clark, Echinoderms from Loiter California. 187 



ASTEROIDEA. 



Eremicaster tenebrarius. 



Porcellanaster (Eremicaster) tenebrarius Fisher, 1905. Bull. Bur. Fish., Vol. 24, 

 p. 293. 



Eremicaster tenebrarius Ludwig, 1907. Zool. Anz., Vol. 31. p. 318. 



There is a single specimen of this species in the collection. It has R = 

 25 mm. and r = 8 mm. Each of the superomarginals carries a conspicuous 

 spine. There is only a single furrow spinelet on each adambulacral plate, 

 but the segmental papillae are conspicuous nearly to the end of the arm. 

 The terminal plate has only three spinelets. There are but ten supero- 

 marginal plates. In all these points, this individual resembles Alaskan 

 specimens more closely than it does those from California. 



Station 5684. Southwest of Santa Margarita Island, west coast of 

 Lower California, 1760 fms. 



Eremicaster pacihcus. 



Porcellanaster pacificus Ludwig, 1905. Mem. M. C. Z., Vol. 32, p 89. 

 Eremicaster pacificus Fisher, 1907. Zool. Anz., Vol. 32, p. 14. 



Both adults and young are represented in this series, the largest having 

 R = 24 and the smallest, R = 8. As the latter is considerably smaller 

 than any hitherto described, a few details of its structure may be worth 

 recording. There are eight or nine adambulacral plates but only five or six 

 marginals. Most of the superomarginal plates carry a spine and the adam- 

 bulacrals usually have two, but the distal ones may have only one. The 

 terminal plate of each arm carries five spines, of which the median is If mm. 

 long. The median cribriform organ is made up of eight to ten lamellae 

 but the lateral ones are much less developed and have only four to six 

 lamella?. The madreporite is large and the periproctal tube is 2\ mm. long. 



Station 5673. Off Pt. San Tomas, west coast of Lower California, 

 1090 fms. 



Station 5691. Off Pt. San Tomas, west coast of Lower California, 

 868 fms. Bottom Temp., 37.2°. 



Station 5692. Off Pt. San Tomas, west coast of Lower California, 

 1076 fms. Bottom Temp., 37.1°. 



Eleven specimens. 



