330 BULLETIN 76, UNITED STATES NATIONAL MUSEUM. 



differing in several imi)ortant details. So far as the limited number of specimens 

 allows one to judge, these diflercnces are constant. Solaster japonicus, new species, 

 differs from Solaster papposus in having more numerous and less prominent mar- 

 ginal plates, and seven to nine furrow spinelcts (four in North Pacific papposus). 

 Rays ten, rarely nine. A large specimen (R = 80 mm., r = 40 mm., R = 2 r) has 

 twenty-six to twenty-eight marginals, while papposus of the same size have eighteen 

 to twenty. Typically these marginals are separated by less than their own width, 

 form a very regular series, their spinelets being very numerous, the peripheral quite 

 short, and the rest graduated toward the center ones, which are decidedly shorter 

 than the subambulacral spines. In some specimens the marginals are decidedly 

 compressed and the longest spines near the ventral side of the paxilla. The adam- 

 bulacral furrow spinelets are shorter than the actinals, less heavy, and in a regular 

 comb, the middle members the longest. The spinelets are joined by a web nearly 

 to the tip, the edges of the web forming around the end of each spinelet a flattened 

 pad or flap. This web is joined by the transverse web of the actinal comb, a 

 pecuharity not observed in North Pacific papposus. As a result the furrow and 

 actinal series of adambulacral spines are more or less closely joined. In the actinal 

 series are seven to nine tapering spinules (six in small specimens), longer and stouter 

 than the furrow spinelets, webbed for about half their length, the web continued 

 as a flange of tissue over the pointed tip of each spine. Mouth plates with twelve 

 to fourteen webbed marginal spinelets, the inner two or three abruptly the largest; 

 suboral spinules four to nine webbed, but not connected with the marginal series. 

 They are variable in length, though longer than the shorter marginals. Actinal 

 interradial areas paved \vith numerous small, four to eight spined paxillse, wliich 

 do not extend far along ray. Abactinal skeleton open meshed as in papposus, the 

 paxillae being of the same general type. Paxillaj numerous Avith long central and 

 short peripheral spinelets (apparently deep-water examples have longer spinelets). 

 No well-defined midradial series larger than the rest. (See pi. 9.5, figs. 1 and 2.) 

 Eighteen specimens of this species have been examined from the following locaHties: 

 Station 4818 {type-locality) , off Sado Island, Sea of Japan, 225-245 fathoms, fine 

 brown mud, eleven specimens; 4859, off Matsushima, Sea of Japan, 93 fathoms, 

 green mud, one specimen: 4860; same locaUty, 122 fathoms, green mud, one speci- 

 men; 4867, Sea of Japan (36° 31' N.; 129° 46' E.), 150 fathoms, green mud, four 

 specimens; 4871, Sea of Japan (36° 29' 30" N.; 129° 43' 30" E.), 60 fathoms, one 

 specimen. 



Type.—Gfxi. No. 27788, U.S.N.M. 



Genus HETEROZONIAS Fisher. 



Ileterozonias Fisher, Ann. and Mag. Nat. Ilitit., ser. 8, vol. 5, Feb., 1910, p. 172. Type, Crossasler 

 allemalus Fisher. 



Diagnosis. — Solasteridaj with a wide-meshed abactinal skeleton, and small 

 pseudo{)axilla3 like Solaster, but differing from that genus in having a complete series 

 of actinal intermediate plates to tip of ray and in the arrangement of marginal 

 paxilliE, which consist of transversely oriented prominent inferomarginaJs alter- 

 nating with longitudinally oriented less prominent superomarginals, all in a single 

 linear series. Adambulacral armature as in Solaster. Papulae numerous and 

 prominent. 



