STARFISHES OF THE PHILIPPINE SEAS. Ill 



the diagnosis, and from Leyty chaster in having armed inferomargi- 

 nals of the type of Psilaster and Persefhovxister. I should be in- 

 clined to rank Astromesites with BlaJciaster were not the abactinal 

 2)lates wholly different. 



Cenus PERSEPHONASTER Alcock. 



Fersephonaster Wood-Mason and Axcock, 1891, p. 430. Type, P. croceus. 

 Psilasteropsis Fishee, 1906, p. 1023. Type, Ps. cingulatn Fisher. 



KEY TO THE SPECIES OF PERSEPIIONASTEU HEUEIN DESCRIBED. 



ft \ Marginal plates broad and conspicuous, the inferomargiuals forming a wide 

 bevel to actinal surface and bearing, on the outer tumid end, which pro- 

 jects laterally beyond superomarginals, a prominent comb of slender 

 spines, covering, at least proximally, a second smaller parallel comb ; 

 superomarginals with a transverse series of appressed spines or spinules. 

 b \ "With several spines on the actinal surface of inferomargiuals in addition 

 to the lateral comb. 

 c \ Rays broad and petaloid, abruptly narrov,-ed to a very attenuate ex- 

 tremity ; pasillar area broad ; actinal intermediate plates extending 

 fully two-thirds the length of ray, and larger ; inferomarginal plates 

 wider; superomarginal spines more prominent and numerous. 



euryactis, p. 112. 

 r ^ Rays narrower, evenly tapered; paxillar area narrower; actinal inter- 

 mediate plates extending a little over one-half length of ray, and very 

 small distally ; inferomarginals narrower ; superomarginal spinules 



inconspicuous luzonicus, p. 118. 



&^ Only the lateral comb of inferomarginal spines (except on first 3 or 4 



plates) anchistus, p. 117. 



G*. Marginal plates massive, but not especially broad, the side of ray vertical ; 

 rays slender, more or less attenuate at tip ; second lateral comb obsolete ; 

 superomarginals unarmed or with single spine, not a transverse series. 

 b \ Superomarginals not conspicuously tumid and without special spine ; no 



abactinal pedicellariae independent of paxillae tenuis, p. 121. 



h ^ Superomarginals tumid, with a single spine, forming a straight series 

 along ray ; among the paxillae low plates bearing fasciculate pedicel- 

 lariae independent of paxillae ; no erect lateral spine above the infero- 

 marginal comb. 

 c \ Superomarginals very tumid with the transverse ridge situated at mid- 

 dle of plate, and evenly rounded from inner to outer edge; furrow 

 spines 9 ; marginal fan of oral spines, 8 or 4, not prominent. 



multicinctus, p. 123. 

 c". Superomarginals less tumid and with the transverse ridge situated be- 

 tween center and distal margin of plate ; an appreciable angle between 

 the dorsal and lateral surfaces ; inferomarginals broader, with less 

 crowded, slenderer squamules ; furrow spines 7 or 8 ; marginal fan 



of mouth spines 5 to 7, prominent suluensis, p. 125. 



h '. Marginals tumid, the inferomarginals being narrow and provided usually 

 with an erect conical spine at upper end of plate, above the appressed, 

 longer spines of the lateral comb ; superomarginal spines in a single 

 series along ray, passing from the inner edge of plate toward outer, 

 after the fifth plate monostoechus, p. 134. 



