52 ART. 1. 1. IJIMA : HEXACTINELLIDA, III. 



of the discohexaster under consideration are found occasionally 

 such forms as resemble the two shown in figs. 35 and 36, PI. 

 III. They grade over to the more usual spherical discohexasters 

 through intermediate forms. Those, of which the one figured iu 

 fig. 35 may be taken as a representative, are unusually large (up 

 to 114/^ diameter) and have long, slender terminals, 7 or 8 in 

 number to each principal. Spicules like fig. 36 are more rarely 

 seen ; in these, each principal possesses usually three somewhat 

 bent terminals, the discs of which have marginal teeth appre- 

 ciably larger than usual. 



Of inconstant occurrence in the species is the small and delicate 

 form of hexasters, represented in fig. 31, PI. III. AVe have here 

 to deal with a rosette which is very much like a floricome in 

 appearance but differs from it in the fact that the terminals end 

 n insignificant pinhead-like knobs, instead of toothed plates. For 

 the sake of reference we may call it a tylfloriconie. Diameter 38- 

 50 /^. Principal slender ; in length about 1 that of the entire ray, 

 or shorter. Terminals very fine, slightly thickened towards the 

 outer knobbed end ; 7-10 in a whorl to each perianth, which is 

 narrow but outflaring at the outer end. I first became aware of 

 the presence of the tylfloricomes in the specimen (No. 434) from 

 Onigase, in which they are tolerably common, especially near the 

 gastral surface. Not infrequently a tylfloricome is found shifted 

 right to, and hanging on, the tip of the freely projecting ray of a 

 gastralia, after the manner of floricomes on Euplectellid dermalia. 

 A subsequent search in the Okinose specimens revealed the oc- 

 currence of the same hexaster, though never more than sparsely, 

 while in some cases it was entirely absent. 



