ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS — FISHER. 211 



a shallow sulcus running from the center of the plate to each interradial angle. 

 The plates are entirely free from one another, those of the raiiial and either adradial 

 series being lengthened transversely, the others rounder. In the vicinity of the mar- 

 ginal plates they become more crowded and lengthened longitudinally. In the 

 center of disk the plates are roundish, and in the narrow interradial area c|uadratc, 

 hexagonal roundish, lozenge-shaped, or, near margin, oblong. In the proximal 

 portion of the radial areas, small secondary plates or paxiliff', with narrow ossicle- 

 like bases, arc interspersed rather irregularly, but form a fairly regular series between 

 the radial and either adradial row of plates. The low tabulum surmounting each 

 plate is slightly convex, hexagonal to elliptical on radial areas, roundish to irreg- 

 ularly quadrate intcrradially, elliptical and compressed near border, and bears a 

 central group of robust, flat-topped, ((uadrate or polygonal granules (about ten 

 to fifteen on radial plates) surrounded bj' a peripheral series of smaller, square- 

 tipped, flattened regular granules. The granulation does not appear crowded. 

 Nearly all tlie plates bear one or two delicate pedicellarise with thin wide-spatulato 

 jaws, liigher than the granules. At the edge of the disk where the plates are very 

 irregular, only the marginal series of granules may be present on account of the 

 compression of the plate. The papuhc are conspicuous on account of the open 

 character of the tabulate armature, and are distributed as in C. japonicus. The 

 abactinal juembrane is rather flexible, the plates not bemg in contact. 



Marginal plates more or less elongate and, owing to the thinness of the disk, 

 rather small; except for the first two or three plates, the members of the two series 

 alternate. Superomarginals, fourteen in number from each interradial line to 

 extremity of series, or twenty-eight to each side of disk, about as high as broad, and 

 much longer than high, except at the end of the series, where they are shorter. 

 These plates form a narrow border to the abactinal area and are covered with a 

 rather uniform, dense, polygonal granulation, a peripheral series being readilj^ 

 distinguishable. The outer plates, or sometimes all, have a small naked area on 

 abactinal face, bearing one to tliree smaU, two-jawed pedicellariae, larger than the 

 granules. Sometimes on the proximal plates onlj' a narrow area about each is 

 left free by the granules; lower margin of each superomarginal angular, forming 

 two facets for articulation with two inferomarginals. 



The inferomarginals, sixteen to a ray or thirty-two to a side, are nnich wider 

 than high, and encroach farther upon the actinal area than do the dorsal series 

 upon the abactinal. The total width of the plate in large specimens is often less 

 than the length, but in smaller specimens the width equals, or exceeds the length. 

 This is true of some large examples. In the middle of the actinal surface is a small 

 naked area, increasing in size toward outer end of series, which bears one to three 

 small, two-jawed pedicellaria^, but slightly larger than the granules. There is consid- 

 erable variation as to the extent of the naked areas, which are much reduced on some 

 specimens. Granulation of inferomarginals similar to that of superomarginals. 



Adambulacral plates nearly square with a straight or slightly curved furrow 

 margin. Armature consists typically of a furrow series of eight or seven imtapered, 

 compressed, square-tipped spinelets about half as long as the length of the plate, 

 subequal or slightly shorter at either end, very regular and standing parallel. 

 These spinelets are four-edged, or quadrate in section. On the actinal surface are 

 two irregular longitudinal series of smaller granules, the inner well spaced fn>m 



