ASTEROIDEA OF NORTH PACIFIC AND /UJJACKNT WATEKS FISUER. 277 



and more pointoil at the tip; length of spinelets viiriable. The nimil>er «f s])inelels 

 to each cluster is variable, but few (five to lifleen). Si)nie e.\ujiij)les have the general 

 average nearer the larger number, some nearer the smaller. Papula? one to five to an 

 area, typically one to three. The lateral pseudopaxillse are generally a trifle smaller 

 than the abactinal. 



The marginal plates are clearly defined, forming with tiie aclinal intermediate 

 series three i)arallel series, the upper of wiiich diverges at base of ray to make room 

 for a short intermarginal series. The actinal intermediate jjlafes do not reach the 

 end of ray. They are small, as a rule about half as wide as the inferomarginals which 

 in turn are wider tlian the superomargiuals. Tiie latter series is often more or less 

 irregular and not well defined. As compared with liriiiscitla these three series have 

 much fewer spmelets and are less conspicuous, being more compressed. The infero- 

 marginals, for instance, are shorter in proportion to width than in leviuscula, with 

 about a dozen (frecpicntly fewer) spinelets in two uneven transverse series. There 

 is a series of single intermarginal jnipuhe and one inframarginal (between the infero- 

 marginals and actinal intermediate plates). 



Adambulacral armature sjiarse, consisting of five to eight stubby spinelets, of 

 ■which the inner is the largest, arranged in a single zigzag series or more rarely in two 

 on the outer part of the small ])late. The furrow spinelet is short, papilliform, and 

 situated deep in furrow. Jlouth plates small, with few sjjinelets. 



Madreporic body variable in size, circular, with coarse irregular radiating 

 ridges bearing spinelets. 



Color in life probably variable; a specimen from Attn Island, 1906, is labeled 

 "rich creamy white" (Prof. J. O. vSnyder); others show a reddish tinge in alcohol, 

 which, however, may be entirely duo to the efi"ect of the preservative. Brandt says 

 specimens vary from ''Himmelblau bis zum f'yanblau" upper side, and "Ziimuber- 

 farben zum Fleischfarben" beneath. 



Variation. — There is variability in the thickness of the arms and their relative 

 length as already noted. The abactinal pseudopaxillje or clusters of spinelets are 

 also subject to considerable variation. Specimens from Bering Island have the 

 marginals less regular than typical e.xamples, but the latter also occur among the 

 same lot, so the difTerenco is probably purely individual. Examples from the nearer 

 Aleutians occasionally a[)proach Ifniiscuh in having larger than tyjiical abactinal 

 pseudopaxUlw, but I have never found any specimens tiiat seemed to prove inter- 

 gradation. Perfectly typical eschrkhtii occurs at Kadiak. Examples were taken 

 from a jar containing leviuscula possibly showing that the two forms range together. 



Care of the young. — This form broods the eggs and takes care of the young for 

 some time after they have metamorphosed. The bmod ])ouch is the region about 

 the mouth, formed by arching the disk and bringing the bases of rays tiigether. 

 Into this cavity the eggs arc tightly j>ackeil, and are of course protected by the 

 body of the mother. Specimens coliecled at Agattu, Juno S, and at Attn, Juno 10 

 and 11, 1900, are with eggs, as also a specimen from Xikolski, Bering Island, Juno 1-1. 

 An example collected by the f'oru.-in has the brood pouch filled with young about 

 4 mm. in diameter and with eight j)airs of tube feet to a ray. This specimen is 

 figured. (PI. 68, fig. 1.) 



