120 FISHER 



vate to thimble-shaped, increasing in size toward upper end of 

 plate (same spinelets are markedly squamiform in californicus). 



Armature of inferomarginal plates very similar to that of cal- 

 ifornicus, there being usually 2 or 3 marginal spines obliquely 

 placed, and, in a line, 3 more spaced, smaller, spines along 

 aboral edge of plate. The auxiliary lateral spines situated just 

 adorad to the regular lateral spines on each plate are longer 

 than the same spines of californicus. 



Adambulacral furrow spines 3 or 4, similar to those of cal- 

 ifornicus. First actinal series with 2 spines, the aboral being 

 much the longer, tapering, slightly flattened, bluntly pointed, 

 longer and slenderer than the corresponding spine of califor- 

 nicus. The adoral member is about as long as the furrow 

 spine which stands vis-a-vis. Outer or second actinal series 

 usually consists of 3 slender untapered spines somewhat shorter 

 than furrow spines, and standing in a fairly regular row. 

 Near base of furrow 2 or 3 very small spinelets sometimes 

 stand on outer end of plate. 



Mouth spines similar to those of californicus, but the mar- 

 ginal series stand slightly spaced from the intermediate spines, 

 so that inner end of combined plates is broader and the 3 series, 

 superficial, intermediate and marginal, are more clearly evi- 

 dent. All spines are slenderer and a trifle longer than in cal- 

 ifornicus. Marginal spines, about 7 between tooth and inner 

 end of first adambulacral plate ; and about 6 or 7 more minute 

 spinelets continue the series two-thirds distance to outer end of 

 plate. 



Madreporic body concealed by paxillae, situated as in cali- 

 fornicus and crossed by sinuous strias ; tiny, spiniform knobs on 

 ridges of californicus apparently lacking. 



Color in alcohol, bleached yellowish to whitish ; color in life 

 unknown. 



Type, No. 21927, U. S. Nat. Mus. Type locality, vicinity 

 of Santa Barbara Islands, in 150 fathoms. The vertical range 

 is 67 to 162 fathoms, and the species extends south to Lower 

 California at least, and north to the latitude of Monterey Bay. 



Remarks. — This species differs from A. fragilis Verrill in 

 having numerous actinal adambulacral spines and shorter rays. 



