28 Proceedings of the Biological Society of Washington. 



The characteristic feature of this species is the presence of elevated 

 abactinal plates with robust conical spines, forming conspicuous pro- 

 tuberances, very variable in number. 



Pteraster corynetes new species. 



Diagnosis. — Abactinal surface resembling superficially that of P. pul- 

 villus ; probably more nearly related to P. semireticulatus . Paxillee with 

 low pedicel surmounted by 7 or 8 longer, radiating, peripheral spinelets 

 surrounding a central shorter one; tips of peripheral spinelets united by 

 fibrous tissue ; spiracula in lines between spinelets ; no deposits in supra- 

 dorsal membrane; furrow fans with 7 spines (distally, 6); actinolateral 

 spines stout, the tips defining ambitus ; 5 oral spines, the 10 united by a 

 continuous membrane; suboral spine may be entirely lacking; when 

 present, slender, tapering. Rays 5; R=24 mm., r=13mm., R=1.8 r; 

 breadth of ray at base, 14 or 15 mm.; thickness of disk, 9 mm. 



Type.— Cat. No. 37,014 U. S. N. M. 



Type-locality .—Station 5623, Molucca Passage, 7.5 miles northeast Mak- 

 yan Island (0° 16' 30'^ N., 127° 30' E. ), 272 fathoms, fine sand, mud ; 1 

 specimen. 



In my key to the species of Pteraster (Asteroidea of the North Pacific, 

 p. 368), P. corynetes belongs to the second section, although the rays are 

 slightly longer than in the other species. Among those species having 

 all the oral spines united by a continuous membrane, only 5 are com- 

 parable with corynetes, namely pulvillus, temnochiton, rugatus, semire- 

 ticulatus, and ingolfi, to none of which it is closely related. 



Pteraster obesus myonotus new subspecies. 



Diagnosis. — Closely related to P. obesus H. L. Clark, of Japan, and 

 resembling superficially P. pulvillus Sars. Differing from obesus in being 

 nearly pentagonal in form, in having a fairly tough supradorsal mem- 

 brane in which there are well developed bands of muscle forming a 

 reticulum of hexagons and triangles; and in having fewer paxillar spines 

 (7); adambulacral spines 5 (6 on the first few plates), the innermost very 

 short; 7 or 8 free oral spines, the innermost flattened and truncate; 

 suboral spine sharp, a little longer than longest oral spine, and with the 

 distal half hyaline, tapering, three-edged. R=28 mm.; r=24mm.; R 

 =1.2 r. 



Type.— Cat. No. 37,015 U. S. N. M. 



Type-locality.— Station 5518, Mindanao Sea, off" Point Tagalo, 200 fath- 

 oms, gray mud, globigerina; bottom temperature 54° Fahr. 



Diplopteraster multipes patagiatus new subspecies. 



Diagrnosis.— Closely resembling D. multipes, but differing in having 

 narrower paxillar areas (exclusive of actinostomial membrane) and in 

 having the same number of spines in both sorts of furrow combs (or if an 



