ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS — FISHER 35 



marginal and four actinolateral series — and all are precisely similar to the supero- 

 marginals. On the outer portion of ray the actinolateral series are successively 

 reduced to three, two, and finally at end of ray to one. Each of these plates, including 

 the marginals, bears a very slender, delicate, sharp spinule, which increases in length 

 toward the furrow, that on the proximal superomarginals being 2 mm. in length, and 

 that nearest the furrow in the same transverse series, nearly 4 mm. The general 

 surface of the plates is covered with very delicate, short, spaced, often curved spine- 

 lets, and there are one or two rather prominent pedicellariae to each plate, forming 

 fairly regular longiseries along the ray, between successive series of plates. The 

 median radial plates bear two to five pedicellariae each. Papulae inconspicuous, one 

 or two to the pore, usually one. Papular areas very small. 



The prominent adambulacral plates bear a transverse series of three to five 

 spinelets. The inner two are short, stout, and pointed, and are borne on the furrow 

 projection. The inner has a terminal membranous expansion bearing sLx or eight 

 pedicellariae of graduated sizes. The second bears one similar much larger pedicellaria 

 or occasionally two, near the base of the spinelet. The next or first subambulacral 

 spinelet is larger, and is slender and pointed, the two following being successively 

 shorter. On the outer part of ray, only two subambulacral spinelets are commonly 

 present, and the second furrow spinelet is often missing. The alternate, nonpromi- 

 nent, plates have a small furrow spinelet, bearing one or two small pedicellariae, 

 situated near the adoral edge, and on the actinal surface a transverse row of two 

 spinelets very similar to those of the prominent plates. A large pedicellaria some- 

 times stands at the outer end of the series. 



Madreporic body convex, subtubercular, circular, situated 7 mm. from center of 

 disk. 



Anatomical notes.- — There is an incipient dorsal stomach pentagonal in outline, 

 and a saccular stomach proper with a short rounded lobe in each ray. From the 

 corners of the dorsal division depart the two slender hepatic coeca which extend 0.6 

 the length of ray. Interradially, between the points of departure of the hepatic 

 coeca, the dorsal stomach is outlined by a prominent fold. The radial sacs of the 

 ventral stomach are attached to the prominent knob of the first two pairs of ambula- 

 cra] ossicles by numerous strands. Intestinal caecum consists of three tubular 

 structures, 10 to 15 mm. long, springing from a common center. The opening from 

 this small central chamber into stomach is prominent. Gonad long tubular with a 

 few irregular lateral branches; it opens intermarginally at base of ray a short dis- 

 tance from the interradius. Interradial septum rudimentary, membranous. Ampul- 

 lae double; that is, consisting of two divergent divisions springing from the central 

 portion of the pore. No Polian vesicles; Tiedmann's bodies present. No super- 

 ambulacral ossicles present. (Specimen from station 2919 examined.) 



Variations. — The largest specimen from station 2919 is oidy slightly bigger than 

 the type, but the rays are noticeably broader and the adradial series of plates is not 

 quite so much encroached upon by the neighboring scries as in the type. The lobes 

 of the superomarginal and carinal plates do not come within 0.8 to 1 mm. of touching. 

 R 155 mm., r 12 mm.; breadth of ray slightly beyond base, 12 mm. 



The example from station 4765 has the following large dimensions: R 178 mm., 

 r 11 mm. R=16 r; breadth of ray, a little beyond base, 14 mm. This specimen is 



