800 



of any enlarged spines or tubercles. Inferomarginal plates rather narrow 

 with a transverse aboral series of about 3 spines on edge of ray, con- 

 tinued inward along aboral edge of plate by 2 to 4 smaller spaced 

 spinules; 4 or 5 auxiliar}- sj)inules, just in front of lateral spines, form 

 an additional armature to margin of ray. Paxillae are small to medium 

 sized, about 4 or 5 transverse series corresponding to 2 superomarginals 

 at base of ray, 6 or 7 at middle, and about 8 or 10, to every 2 supero- 

 marginals near tip. Paxillae are largest on outer half of radius of disk, 

 decreasing in size towards center of disk, very quickly toward margin, 

 and gradually along rays toAvard tips; arranged in definite transverse 

 rows along sides of area, elsewhere more compact and without order. 

 Each paxilla pedicel is surmounted by 15 to 20 short, stout, round-tipped 

 on subtruncate, often davate, spinelets in a peripheral series and 8 to 15 

 in center. Some specimens have only 8 to 15 spinelets in peripheral 

 series and o to 8 in the central group on the larger paxillae. Opposite 

 suture between second and third superomarginals about 18 to 20 paxillae 

 can be counted across ray. 



Adambulacral spines in about 3 parallel series (sometimes 4). 

 (1) Furrow spines 3, the central longest. (2) First actinal series consists 

 of 2 (or 3) slightly shorter spines, of which the aboral is very much 

 the stouter, being flattened with a rounded or truncate tip. (3) On 

 outer half of plate are 2 to 5 shorter slightly flattened spines either in 

 an irregular group, or forming a series 2, or a series of 3, with 1 out of 

 line, additional. First adambulacral plate is much compressed. 



Madreporic body is partly concealed by jjaxillae and is situated 

 Ys distance from margin to center of disk; striations are deep, irregu- 

 larly centrifugal and ridges are beset with numerous little knobs. 



Color in life, ferruginous to light claret brown above, lighter below. 



Habitat. Monterey Bay, California, 140 metres or less. 



Remarks. This species differs from A. fragilis Verrill (Panama) 

 — a slender-rayed form — in having numerous actinal adambulacral 

 spines, fragilis possessing but a single stout pointed spine on the actinal 

 surface of adambulacral plates. A. regalis Gray (San Bias and south) is 

 a short-rayed form (E. = 3 rj, and has but 1 sharp actinal adambulacral 

 spine. A. verrini de Loriol (Mazatlan) is also a comparatively short- 

 rayed form (R = 3,4 r) and departs otherwise from californicus in having 

 a different inferomarginal armature, as well as a single small tubercle 

 on each of the superomarginals, forming a longitudinal series along ray. 



Alexaudraster inflatus n. sp. 



Rays 5. R = 60 mm; r == 23 mm. R = 2,6 r. Breadth of ray at 

 base, 27 mm (more than r!). 



