62 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



which a new subfamily has been made. The Astropectininae lack the 

 webbed marginal and actinal fascicles of Craspidaster. While the 

 name was coined by Sladen, the subfamily as here used is more ex- 

 tensive than his, as it includes several of his Archasteridae as well as 

 subsequently described groups. For a discussion of this family see 

 Fisher, mid, p. 37. 



Genus ASTROPECTEN Gray. 



Astropecten Gray, 1840, p. ISO. 



KEY TO THE SPECIES OP ASTBOPECTEN HEREIN DESCEIBED. 



a\ Superomarginal spines in a single definite series continuous throughout ray, 

 with exception sometimes of second, third, and fourth plates. 

 &\ Superomarginal spines upright and prominent, proximally equaling or ex- 

 ceeding height of plate ; no conspicuously enlarged subambulacral spine. 

 c\ The second, or second and third, superomarginals without spines; infero- 

 marginals with 4 or 3 large bristling spines in a transverse series; 

 superomarginal spines 1.5 to 2.5 times height of plate. 



polyacanihus, p. 63. 



c*. Superomarginal spines continuous throughout ray ; inferomarginal plates 



with 3 lateral spines and spaced therefrom, 1 on the actinal surface. 



phragmorus, p. 65. 

 y^. Superomarginal spines small, much less than height of their plate; one of 

 the subambulacral spines conspicuously enlarged. 

 c*. Superomarginal spines all on inner edge of plates ; 1 lateral spine with a 



small companion tnindancnsis, p. 67. 



(f. Superomarginal spines of first few plates at inner edge, thence moving 

 to angle between lateral and dorsal surfaces of plate; some plates 

 with occasionally 2 spines ; lateral spines 2 or 3, with proximally 1 or 



more smaller actinal companions inaequalis, p. 69. 



o*. Superomarginal spines small, confined to first, or first 2 or 3 plates, or ex- 

 tending over half the length of ray, but not the entire length. 

 b\ Rays short and stout ; R less than 5 r ; superomarginal spines on first, or 



first 2 or 3 plates only velitaris, p. 70. 



&'. Rays long and slender; R more than 6 r; superomarginal spines on a few 

 proximal plates or on all but the last third of ray. 

 c^. Subambulacral spines 3 or 4, none enlarged ; superomarginal spine at 



base of ray only ; mouth spines in regular series lusonicns, p. 82. 



c*. Superomarginal spines on all except outer third of ray; subambulacral 

 spines more that 5, one in the first series enlarged ; mouth spines 

 irregularly arranged. 

 d\ No superomarginal or inferomarginal pedicellariae ; abactinal and 

 adambulacral pedicellariae very few ; paxillae medium-sized ; supero- 

 marginals of proximal half of ray not longer than wide; lateral 



spines 3, sometimes 4 tenellus, p. 84. 



d\ Numerous abactinal, superomarginal, inferomarginal, and adambula- 

 cral pedicellariae; superomarginals of the proximal (as well as 

 distal ) half of ray longer than wide, except the first 8 or 9 plates ; 



lateral spines 4, 3 on distal third of ray pcdicellaris, p. 87. 



b'. See also monacanihus and cucnciiiis, where a small spine may occur 

 aberrantly on the first, or first 2 or 3 plates. 



