2^^orth Pacific Zoioasteridoe. 391 



ndnmbulacral plates with a transverse series of five spitiep, 

 tlio tii.st ili'op ill furrow, the second witli a pedicellaria about 

 1'.') nun. long uttnclietl to its bnso. 



7>/>e-/.>ca/i/y.— 53° 12' N., 171° 37' W., 43*5 miles north- 

 w.st of west point of Yunaska Inland, Aleutian I.ilands, 

 1217 fatlioins, tine black sand; bottom temperature 35'2° 

 F.dir, (U.JS. Fisheries steamer * Albatross/ I'JOG). 



Zoroaster evermanni mordax^ subsp. n. 



Closely resembling Z. evermanni* ^ but differing in having 

 more robust primary spines (which are typically also a little 

 shorter nctinolateraily), and in having on the second from 

 inner spine of prominent adambulacral plates a largo pedi- 

 cellaria (or sometimes two), from I'D to 2'5 mm. long, and 

 conspicuously bigger than the cluster of small peilicellariaeon 

 the turrow-spine. 11 = 153 mm., 7-=10+ mm., R = 15r. 



7;v/>p-/''ca//V.y.— Off Washin-(on,47° 28' X., 125° 15' VV., 

 477 fathoms, green mud. 



Tiiis race is distributed from off Washington to southern 

 California. At the southern end of its range it is found 

 only in water deeper than 600 fathoms, while the typical 

 evermanni occurs from San Diego, California, to Santa Cruz 

 Island, California, in 21tj to 510 fathoms. 



Key to the North Pacific Species and Subspecies </ 

 Myxoderma. 



a. Size large (R, 200 iiim.V Tl)e jilates hiuI 

 sninett invested in h thick piiljiy membraue, 

 slimy in life; abactinal pupulm ftreurt lar;,'e, 

 the tlor!>nl skeleton being open and rather 

 irregularly reticulate at base of ray ; 

 itbactinal plates without accessory spinelets 

 to any extent; actinulateral spines pointed, 

 tapered, sometiniL-s somewhat llattined, 

 but never spatulate ; terminal plate lar<,'e, 

 ovoid, especially conspicuous in young 

 specimens ; rays attenuate distally. 

 b' . llays thicker and skeleton stouter, third 



or lowest series of actiuolateral plates 



extruding tive-eighths the length of ray ; 



abactinal spines robust and stubby ; 



♦ Zoroatttr evntnanni, Fisher, Bull. Bureau Fisheries, 1{K)4, vol. xiiv., 

 June 10, 1"J06, p. yi7. Further investigatitu has shown that this is not 

 II Myxoderma, as it lacks the essential anatomical characters of that 

 genua. 



2(^^ 



