ASTEROIDEA OF NOKTH PACIFIC AND ADJACENT WATERS FISHER. 313 



Remarks. — As the foregoing deseription is largely- a comparison of stimpscmi 

 and endeca it will not he necessary to state again the (lifferenres wliich separate 

 the two forms. It is not possible to determine satisfactorily the relationship of 

 the two species. Althoiigli the extremes are certainly verj- distinct, at Kadiak 

 Island they either hybridize or approach each other more closely than elsewhere, 

 judging by nine dried sjiecimcns in the collection. The Bering Island specimens 

 are not typical siimiisoni as the rays are too short and the marginal plates larger 

 than in typical specimens. The abactinal ])axilla> resemble those of stimpsoni. 

 These specimens may really be only a variety of endeca with unusually large paxillse. 



SOLASTER DAWSONI Verrlll. 

 PI. 84, figs. 1, 2; pi. 85, figs. 1, 2; pi. 86, figs. 1, 2; pi. 113, fig. 1. 



SolasUr dawsoni Verbill, in Appendix C, Report of Progress, Geol. Surv. of Canada for 1878-79, 

 1880, p. 193 J.— J. F. Whiteaves, Trans. Roy. Soc. Canada, vol. 4, sec. 4, 1886 (1887), p. 

 lie (Powell Island, Straitu of Georsia, Melaspina Inlet, Johnstone Strait, Goleta.- Channel). 



Solaster endeca Murdoch, Report of the International Polar Expedition to Point Harrow, .\laska, 

 1885. p. 159. 



Diagnosis. — Rays eight to tliirteen (commonly eleven or twelve) stout; disk 

 moderately lai^e. A large specimen: R = 163 mm.; r = 48 mm.; R=3.4 r. R 

 varies to 2.5 r. Differing from S. endeca in having larger, more spaced, and tabulate 

 pseudopaxillie, larger marginal plates with more numerous spinelets, smaller actinal 

 interradial areas, and especially in having much longer furrow spimdes and longer 

 bristling actinal adambulacral spines in a straight transverse series. 



Description. — Rays variable in number, but usually eleven or twelve, less 

 often thirteen, ten, nine, or eight. The width varies with the number, being greater 

 when the number is small. T^^iical specimens have the pseudopaxillie much larger 

 and more chstantly spaced than in endeca, tabulate in structure, and resembling 

 superficially in alcoholic specimens the parapaxilla' of Mediastcr. They are ellip- 

 tical or roundish in contour, largest on disk and i)roximal jiortion of rays, decrejising 

 in size toward the end and sides of rays, being arranged in regidar quincunx on the 

 lateral portions of the rays. In endeca the pseudopa.xiihe decrease in size toward 

 the center of disk, but in dawsoni they are subequal, or slightly larger. The ptvxilla' 

 vary considerably in size in different localities and the number of spinelets and 

 their length is also variable. An example from Monterey Bay hiis on the larger 

 paxillte of disk, surmoimting the low tabulate eminence of the plate, sixteen to 

 thirty peripheral and five to fifteen central, short, rough-tipped stubby spinelets so 

 immersed in membrane that only the tips protnide and give a granuliform appear- 

 ance, the summit of the group being usually flat. The spinelets themselves are 

 longer than the height of the tabiilum, and usually but not always shorter than 

 width of large paxillse. A variet}- from deeper water (stations .3459, 3466) has the 

 paxilhe more convex and the spinelets more diverging, and less compact. The 

 spinelets are sometimes much less numerous, ten to twenty to a paxilia. Papulsp 

 numerous in the meshes of the skeleton, five to ten or even more on disk and usually 

 one to five on rays except distally where there are only one or two. Very large 

 specimens may have as many as twenty ])apula;> to an area near center of disk. 



