118 



BULLETIN 70, UNITED STATES NATIONAL MUSEUM. 



slioitcr spines may take the place of the pedicellaria. In line with the tooth a series 

 of about ten su])crfieial spinelets follows edge of suture, decreasing in size toward 

 outer end of plate; and along curved margin adjacent to first adambulacral arefour 

 or five slender spinelets, the second from inner end of series often thelongest. This 

 series is separated from the su])eificial by a shallow groove. 



Color in life, reddish brown (burnt sienna) on abactinal surface ; marginal s]iines 

 lighter, often wliitish; actinal surface whitish. 



Anatomical notes. — Supcrambulacral ])lates present, well developed, absent from 

 first ambulacral ossicle. Gonads extend, in a series along either side of abactinal 

 integument, to tip of ray; individual tufts short, with few thick tubules. No intes- 

 tine; no intestinal coRCum; no anus. Stomach not divided into dorsal and ventral 

 compartments. Tube feet large, pointed, without calcareous deposits in their walls. 



Variations and young.— A. specimen with R =31 mm. differs from the foregoing 

 description in having two marginal spines to plate, the third being sometimes repre- 

 sented by a much smaller spinule. Outer adambulacral spinelet is reduced in size, 

 and the otliers are relatively longer than in the bigger specimens. Actinal inter- 

 mediate pedicellaria) are confined to basal half of ray, although a few are scattered 

 on distal portion. Abactinal ])ediceilari8e few or absent. A very small specimen 

 (R = 16 mm.) has two series of marginal spines along ray, the outer spines usually 

 the longer; actinal pedicellarise do not extend far onto ray; paxillse small and 

 spaced; no abactinal pedicellariie. 



Specimens vary considerably in respect to the abactinal {)edicellaria3. In the 

 ty])e they are numerous, but some large examples lack them on the superomarginal 

 and adjacent paxillif . 



Type.— Cat. No. 21929, U.S.N.M. 



Type-locality. ^Albatross station 3148, off central California in 47 fathoms on 

 brown mud. 



Distribution. — From north of ifonterey Bay, California, south to Los Coronados 

 Islands, Lower CaUfornia, 11 to 339 fathoms. 



Specimens examined. — Seventy-one, from the following stations (C'alifornia, 

 except as noted) : 



Specimens of Luidia asthenosoma eramined. 



Depth. 



Nature of bottom. 



mud 



fine gray saud, mud 



rocks, sand 



mud 



gray sand, shells . . . 



fine gray sand 



coarse mud 



fine gray sand 



rocks, broken shells 



brown mud 



gray sand 



U. S. Xat. Mus. 



