36 BULLETIN 76, UNITED STATES NATIONAL MUSEUM 



fairly typical with the exception that there are fewer adambulacral pedicellariae than 

 in California examples; particularly the big pedicellaria on the second furrow spine 

 is wanting except on a relatively few plates at the base of the ray. Rarely spine two 

 carries a group of three or four small pedicellariae like those (four to six in number) 

 on the first or innermost spine. Except at the very base of ray, the tube feet are 

 two-ranked. The marginal and actinolateral spines are delicate, slender and sharp 

 as in the type, 4 to 6 mm. long at base of ray and increase in diameter as the furrow 

 is approached, those of the lowermost two rows being at the base about twice as 

 thick as the marginal spines, as well as about 1 to 1.50 mm. larger. The carinal 

 tubercles are coarse, 1 to 1.25 mm. long, slightly swollen above the base (about 0.75 

 mm. in diameter), truncate or blunt, the end sometimes finely striated longitudinally. 

 The carinal plates form a prominent angular ridge, and the adradials are appreciably 

 sunken. The lobes of the superomarginal and carinal plates broadly overlap the 

 adradials and are separated by 0.75 to 1.25 mm. space at the base of the ray. The 

 pedicellariae slightly exceed the miliary spinelets in length, and are conspciuous, 

 being about 1.25 to 1.50 mm. long; but owing to the investment of the spinelets being 

 a little thicker than in southern specimens the pedicellariae do not appear to be quite 

 so prominent. The spinelets are slender, delicate, curved at the base , and slightly 

 compressed so that they appear to be saber-shaped in many cases. They average 

 slightly over a millimeter in length. The papular areas of the dorsolateral surface 

 frequently have two papulae; those of the four lateral series, one each. 

 Type.— Cat. No. 22,345, U.S.N.M. 



Type-locality. — Station 4387, off San Diego, Calif. ; longitude of Point Concep- 

 tion, 32° 32' 40" N., 118° 04' 20" W.; 1,059 fathoms, green mud. (Albatross, 1904.) 

 Distribution. — From Bering Sea and off southern California ; 989 to 1 ,217 fathoms, 

 mud and fine black sand. Temperature range, 35.2° to 38° F. Recorded by Clark 

 (1913) from 879 to 1,101 fathoms off Ballenas Bay and San Rosario Bay, Lower 

 California; bottom temperature, 37.3° and 38.1°. 



Specimens examined. — Six; one from type-locality: 



Station 2919, 32° 17' N., 119° 17' W. (off San Diego, Calif.); 984 fathoms, gray 

 mud; bottom temperature, 38° F. (Coll. U.S.N.M.); four specimens. 



Station 4765, 53° 12' N., 171° 37' W. (43.5 miles northwest of west point of 

 Yunaska Island, Aleutian Islands); 1,217 fathoms, fine black sand; bottom tempera- 

 ture, 35.2° F. (Albatross, 1906); one specimen. 



Remarks. — Zoroaster ophiurus belongs to the carinatus group of species, in which 

 the rays are very slender, long, and pointed; the carinal series of plates is prominent 

 and more or less carinate; and, particularly, the adradial series is inconspicuous, 

 much narrower than either the carinal or the superomarginal and is strongly en- 

 croached upon by both. No matter how large the specimen becomes, the adradials 

 do not equal the size of the superomarginals. The reduction of the adradials is more 

 pronounced in Z. ophiurus and in Z. carinatus philippinensis than in Z. spinulosus 

 of the Hawaiian Islands. 



Z. ophiurus differs from Z. spinulosus in having the adradial series of plates so 

 nearly covered by the carinals and superomarginals that the lobes of the two latter 

 series nearly touch, and, in fact, are in contact in the type. In ophiurus the pedicel- 

 lariae of the general body wall and disk are twice as large as in spinulosus, more 



