ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS FISHER. 



63 



spicuous of all, a superficial, the latter consisting of a nearly straight scries of four- 

 teen or fifteen short flattened, round or square-tipped, or subacute spines, increasing 

 rapidly in length toward inner angle of plate, where there is an enlarged tooth (or two 

 to each mouth angle). Marginal spines small, forming an angular series of seven 

 or eight, between base of tooth and inner end of first adambulacral plate, thence 

 continued along side of first interadambulacral suture in the form of a few strag- 

 gling very small spinelets. Intermediate series extending whole length of plate, 

 parallel and close to supei-ficial series, against which the much smaller spinelets are 

 often appressed. All spines more acute, anil somewhat slenderer in dried specimens. 



Actinal interradial areas very small, having sbc small i)axLlla to each area, 

 one opposite each of the first three adambulacrals. Each paxillu bears several 

 (four to seven) closely grouped, clavate skin-covered, papiliiforni spinelets. Fewer 

 than six plates may be present. 



Superambulacral plates well developed. The upper edge of the amhulacral 

 ossicles, though sharp, is not produced upward into a thin lamina provided with irreg- 

 ular comb-Hke teeth as in the following species. This fact will serve to distinguish 

 cdlifornims at a glance. A Polian vesicle in each interrailius except that containing 

 the madreporic canal, which has two; the same interradius has two septa. Gonads 

 axillary, not extending along rays. 



Madreporic body partially concealed by paxillse, situated about one-third 

 distance from margin to center of disk; striations deep, irregularly centrifugal; 

 ridges with numerous little knobs. 



Color in life, fen-uginous to hght claret brown above, lighter below. 



Variations. — The chief variation in this species is due to the relative size of 

 specimens, the large examples having long, narrow rays, the small ones having 

 shorter thicker rays. As fully seven-eighths of the specimens from off the southern 

 part of California are small, and the majority of those from Monterey Bay are large 

 it would seem, if one had only a few examples, that the southern form hail shorter 

 rays. Several good-sized specimens collected by the Albatross in 18S9 off the 

 Santa Barbara Islands have rays fulh- as long, however, as average specimens from 

 Monterey Bay, while small examples from the latter locaht}' are of about the same 

 dimensions as equal-sized examples from southern California. It is possible that 

 the region about Monterey Bay is more favorable for the species and that it there- 

 fore develops to larger size than in southern waters. 



Specimens from Monterey Bay of nearly the same size vary in respect to the 

 length and width of ray, some specimens having narrower, or more pointed rays 

 than others, but as sho^vn in the accompanying table these differences are not great. 



Table ghowing variations in Astropecten cali/ornicus. 



