ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS — FISHER 31 



portion the spinelets are normal or only slightly clavate, or spatulate. Sometimes 

 far along ray there are two aboral furrow spinelets. The first 12 or 15 subambulacral 

 spines have a variably modified spatulate truncate, grooved, or incipiently bifid tip, 

 most pronounced on the third to the ninth or tenth, beyond which as the spines 

 lengthen the tip becomes rapidly smaller. From the twelfth to about the twenty- 

 fifth the spines are merely slightly and decreasingly capitate. On the genital region 

 the subambulacral spines are about 2.5 to 3 plates in length. On the outer part of 

 the ray those on plates to which a lateral plate and spine are fastened are short and 

 slender (1.5 to 2 plates long) while on alternate plates the subambulacral is fastened 

 slightly more upon the actino-lateral face of the plate and measures 3.5 to 4 plates in 

 length (as compared to the lateral spine which equals 9 or 10 plates). 



The rays are separated nearly to the mouth plates; only the proximal ends of 

 the first adambulacral plates are in contact. The outer part of the mouth plates 

 does not separate the first pair of adjacent adambulacrals but extends upward behind 

 the joined inner ends of the adambulacral plates to meet the lower end of the inter- 

 radial plate. These upper ends resemble a pair of independent plates. 



Mouth plates with a modified spinelet, like the adambulacral furrow spinelets, 

 at the outer furrow end of plate, and another at the inner actinostomial end, the two 

 enclosing the first tube-foot. Forming a series with the latter spinelet on the actino- 

 stomial margin are two others, variously expanded and leaflike in form, but bent 

 sharply toward the furrow mouth. The innermost is near the median suture and is 

 sometimes quite small. The second is intermediate in size and lies parallel to that 

 which guards the mouth of the furrow. The amount of expansion of these curious 

 spinelets varies a good deal and their form is often irregular and bizarre. On the 

 outer half of each plate is a tapering, pointed, suboral spine equal to the first 3 or 

 3.5 adambulacral plates in length. 



The articulation surface of the ambulacral plates (second pair), where the ray 

 has been broken off from the disk, is small, deeply notched above and below. The 

 articulation surface is not sharply marked off from the two processes below, as in 

 Brisinga. 



Gonads: The ovaries are each a single slender sac about 2 r in length which 

 opens by the proximal end on the side of the ray, nearly 1 r from the interbrachium. 

 There are two ovaries to each ray. The testes, two to a ray, are many-lobed bodies 

 which have a single opening about 1 r from the interbrachium. 



Type.— Cat. No. E. 1416, U.S.N.M. 



Type-locality.— Station 2859, off British Columbia (55' 20" N., 136' 20" W.); 

 1,569 fathoms, gray ooze; bottom temperature, 34.9 F.; 13 specimens. 



Suborder ASTERIADINA Fisher 

 Family ZOROASTERIDAE Sladen 



Zoroasteridae Sladen, Challenger Asteroidea, 1SS9, p. 41G. — Fisher, Ann. Mag- Nat. Hist., 

 ser. 9, vol. 3, 1919, p. 387; Bull. U. S. Nat. Mus. 100, vol. 3, 1919, p. 470— Clauk, 

 Mem. Mus. Comp. Zool., vol. 39, No. 3, 1920, p. 94. 



Deep-water Forcipulata having a small disk and slender, subcylindrical, often 

 long rays, the plates of which are disposed in regular, usually closely juxtaposed, 



