ASTEROIDEA OF ^MORTH PACU'lC AND ADJACENT WATEItS — FISHER. 207 



ously four-sided; actinal iiilormediato podicoUaria' in variable numbers. Adani- 

 bulacral plat«s usually slightly wider than long, with a slightly oblique furrow 

 series of five or six (four to seven) round-tipped, four-sided, often somewhat flat- 

 tened, stout spinelets, frequently graduated in length toward the adoral edge of, 

 plate, or all but the shorter adoral number sube(|ual. Actinal surface with three 

 to five irregular longitudinal series of low granules, those nearest the furrow spine- 

 lets being largest. A bivalved pedicellaria is normally present on most of the 

 plates, the jaws being usually wider than high, but exceptionally higher than wide. 

 The granules of actinal surface of adambulacrals varj' greatly in number and those 

 on the outer half are not in very definite series. 



Madreporic body pentagonal situated one-third distance from center to inner 

 edge of marginal plates. 



Anatotyucal notes. — Anal ojjening present, subcentral surrounded by three 

 to six plates larger than those adjacent. Intestinal coecum large, with eight long, 

 unequal glove-finger-like radiating divisions. Intestine spacious, stomach small; 

 hepatic coeca long, extending two-thirds to three-fourths length of R; quite a 

 sharp distinction between dorsal and ventral divisions of stomach. Gonads very 

 large, bushy, each with four short ducts and four apertures in a line parallel to and 

 a short distance from the tough, uncalcified intcrradial septum. Dorsal muscle 

 bands stout, joining at center of disk. Each band gives off numerous lateral 

 smaller branches, obliquely like the barbs of a feather, on the side toward margin. 

 Polian vesicles large, one in each interradius except that of the madreporic 

 canal; ampullae double; tube feet with large sucking disks. No superambulacral 

 ossicles. 



When the plates which bear the tabula are examined from the inner surface 

 of the stout dorsal integument they are seen to be arranged in very regular rows 

 parallel with the median radial. The radial row and the two on either side have 

 plates with six short, broad, rounded, or truncate lobes. On either side of these 

 the lobes are very soon lost and the plates become circular. All plates are sUghtly 

 spaced and there are no internal connectmg ossicles as in Mcdiaster. Papulse are 

 single and distributed all over the abactinal surface, except in a narrow intcrradial 

 band reaching toward center of disk as far as the madreporic bodj-; they are absent 

 also at the tip of ray; four to six, or even more, occur around each plate, according 

 to its size and shape. 



Variations. — The examination of seventy specimens of this species, including 

 one from off Misaki, Japan, C40 meters, kindly sent by Dr. Seitaro Goto, of Tokio, 

 reveals a considerable range of individual variation. The difl'erences which the 

 American specimens seem to present are greatly overshadowed by individual 

 diiTerences occurring in examj)les from the same station. Sladen apparently had 

 only one specimen, and of course could give no hint of this variation in his excellent 

 description. 



General form, ttc. — Some specimens are more arcuately pentagonal than 

 Sladen's figure and of the same form as his figure of patagonicus. The Misaki 

 specimen is about intemietliate in form. The Washington specimens are less 

 arcuate tiiau many of those from Bering Sea. The abactinal area varies in the 



