ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS FISHEK. 61 



and Troschel, 1842, is a homonj-m of this species and a s^Tionym, according to 

 most authors, of A. polyacanthus of the same writers. It consequently does not 

 affect the validity of Gray's name, which has two years priority. 



ASTROPECTEN CALIFORNICDS Fisher. 



PI. 6, fig.s. 1, 2; pi. 7, fig. 1; pi. 50, fig. 5; pi. 51, figs. 2, 2a. 

 Astropeclen califomicus Fisher, Zool. Anz., vol. 30, June 19, 190G, p. 299. 



Diagnosis.'^ — Rays five. R = 100 mm.; r=lS mm.; 11 = 5.5 r. Breadth of 

 ray at base, 20 mm. (measured between first and second superomarginal plates). 



Disk small; rays long and narrow, j)ointed; interbrachial angles rounded; 

 abactinal surface plane or arched, bordered by narrow margin formed of supero- 

 marginal plates which are confined chiefly to side wall of arm; superomarginals 

 without enlarged spines or tubercles; inferomarginals rather narrow with trans- 

 verse aboral series of about three spines on edge of ray, continued actinad along 

 aboral edge of plate in two to four smaller-spaced spinules; adambulacral spines 

 in about three parallel longitudinal series, the aboral spine of the middle series of 

 two or three conspicuously flattened, round-tipped and stouter than others (see 

 p. 62) ; paxillse small to medium sized, about four or five transverse series, corre- 

 sponding to two superomarginals at base of ray, sLx or seven at middle and about 

 eight to ten near tip. Upper edge of ambulacral ossicles smooth. 



Description. — Abactinal paxillse fairly uniform in arrangement, and usually 

 compact, largest on outer half of radius of disk, decreasing in size toward center 

 of disk, very quickly toward margin, and gradualh" along ra^-s toward tips; arranged 

 in definite transverse rows along sides of paxdlar area of rays, elsewhere without 

 regularity. Cro^vns of paxillse circular or broadly elliptical when spinelets are 

 radiating, more irregular when spinelets stand erect and compact. Each paxilla 

 pedicel surmounted (in larger paxUlas) by fifteen to twenty short, stout, round-tipped 

 or subtruncate, often clavate spinelets in a peripheral series, and eight to fifteen in 

 center. When the spinelets are crowded together the paxilla is flat-topped and 

 the tips of the spinelets resemble flat-topped granules. In many specimens the 

 spinelets are slender and stand on the pedicel more like the petals of a flower. 

 These specimens usually have the paxillfe more definitely spaced, with fewer spine- 

 lets — t€n to fifteen in peripheral and five to eight in the central group. Opposite 

 the suture between second and third superomarginal plates about eighteen to 

 twenty paxillse can be counted across ray to simflar point on opposite side. 



The bases of the paxillae or abactinal plates are subcircular and slightly over- 

 lapping, without pa])uhB between, along midradial areas and central portion of 

 disk. Along the ray this radial area of roundish plates is about five plates wide and 

 is broader than the same region in A. ornatissimus. The plates are irregularly 

 arranged, without evident spaces between except occasionally on disk. On either 

 side of the radial areas the plates are very regularly arranged in transverse rows, 

 are six-sided but much longer than wide; far along ray they become rudely elliptical, 

 with truncate ends, and on disk broader than on base of ray. Faint lobes are 



"Diagnosis and description based on specimen from station 4559, Monterey Bay, California; 22 



to 8 fathoms, fine gray sand. 



