86 ART. T.^-I. IJIMA : HEXAGTINELLIDA, IT. 



Firstly, the oxj^liexasters (PI. VI., fig. o) which are of quite 

 common occiin-ence. Dinmeter, 80-114 p.. Ver}^ rarely I have 

 met with oxyhexasters in which (jne or two of the principals — 

 never all the six (hexactinose) — bore each a single terminal 

 which was bent at base in the well-known manner. The rule is 

 that the six principals bear each 2 or 3, sometimes 4, diverging 

 terminals. Except at base, these are nearly straight ; otherwise 

 they are slightly wavy. Their surface is oljsoletely rough or 

 nearly smooth. I have noticed that the principals are, generally 

 at least, perceptibly longer than those in the corresponding 

 rosette of C. meyeri. But such finer points in the character of 

 the rosette are probably subject to considerable individual varia- 

 tions. 



And secondly, the minute discohexasters (PI. VI., fig. 4) 

 which have been met with in some numbers — by no means 

 abundantly — in the subderinal s})ace. In no other region of the 

 body have they been discovered. Diameter, 40-30 /i. The entire 

 shape is quite spherical, all the terminal discs being uniformly 

 distributed on the surface. Under a high power of the micro- 

 scope the minute terminal disc is seen to l)e supplied with six, 

 and sometimes more, marginal teeth. The numerous fine termi- 

 nals arise from all over the convex surface of the disc at the end 

 of each principal, as is usually the case with the so-called mi- 

 crodiscohexaster of the Ivossellidse. 



