ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS — FISHER 37 



numerous, and the miliary, or secondary, spinelets are conspicuously longer. Even 

 the primary spinules are longer, but the difference is less well marked. Z. carinatus 

 philippinensis lacks the carinal series of tubercles, and the slender acicular supero 

 and infero marginal spines. The miliary spinelets of the Philippine species are more 

 numerous, more compactly placed, and are appressed to the plates. They are less 

 slender and more squamiferous than in ophiurus. The body pedicellariae are incon- 

 spicuous 



Two species from the Pacific Ocean south of the United States must be compared 

 with ophiurus; these are Z. Mrsutus Ludwig, 12 station 3415, south of Acapulco, Mexico 

 1,879 fathoms, and Z. magnificus 13 Ludwig, station 3360, Gulf of Panama, 1,672 

 fathoms. Although Ludwig separates these species in his text by the description 

 of Z. ( = Cnemidaster) nudus, the two are very similar in appearance. Both have the 

 long slender rays of the carinatus type, but the adradial plates are not sunken, or 

 subservient to the carinal and superomarginal series, although the latter slightly 

 overlaps them. In Figure 146 u the adradials are shown as being slightly smaller 

 than the superomarginals. In a ray of the cotype which I have, they are more often 

 slightly larger on the basal part of the ray. Figure 168 I5 shows the arrangement of 

 plates in Z. hirsutus. These two species constitute a magnificus type, differing 

 from the carinatus type in the greater size of the adradial plates, although in general 

 form and in the small size of the papular areas resembling the carinatus type. Z. 

 magnificus differs from Mrsutus in having a few relatively large (2 mm.) abactinal 

 and lateral pedicellariae and three series of actinal intermediate plates. In Mrsutus 

 there are four series of plates between the inferomarginal and adambulacral plates, 

 and numerous small pedicellariae. 



Z. ophiurus differs from these two species in respect to the adradial plates, which, 

 as noted above, are much less conspicuous. In addition it is separable from magnificus 

 by reason of the presence of a fourth actinal series of plates and the absence of the 

 particularly large pedicellariae, relatively few in number. On the other hand, the 

 pedicellariae are larger and more numerous than those of hirsutus, the carinal plates 

 are more prominent and have longer lateral lobes. 



ZOROASTER ACTINOCLES Fisher 



Plate 13, Figures 2, 2a-2c; Plate 18, Figure 1; Plate 20, Figure 1 



Zoroaster actinocles Fisher, Ann. and Mag. Nat. Hist., ser. 9, vol. 3, 1919, p. 390. — Clark, 

 Mem. Mus. Comp. Zool., vol. 39, No. 3, p. 101. 



Diagnosis. — Rays five. R 161 mm., r 11 mm., R=14.6 r; breadth of ray at 

 base, 13 mm. Rays slender, evenly tapered to the extremity, which is capped by a 

 relatively large terminal plate; disk elevated at center; carinal ridge rather promi- 

 nent. Resembling a slender-rayed Z. fulgens but differing in having the plates of the 

 second, third, and fourth actinolateral series smaller, the fourth series being rudimen- 

 tary; in having slenderer superomarginal spines (decidely slenderer than the carinal 

 spines), fleshier spinelets, relatively larger carinal plates, never but one actinolateral 



'• Ludwig, Mem. Mus. Comp. Zoo]., vol. 32, 1905, p. 172, pi. 28, flg. 161, 162; pi. 29, fig. 168. 

 » Ludwig, idem, p. 159, pi. 26, figs. 146-148, pi. 27, flgs. 149, 150. 

 » Ludwig, idem, vol. 32, 1905. 

 u Ludwig, idem, vol. 32, 1905. 



