KHABDOCALYPTÜS VICTOR. 245 



at the upper eud. The next larger is the one depicted in PI. 

 XIX., fig. 17 ; height of body, 37 mm.; wall, 5 mm. thick in the 

 middle ; oscuhim, 7-9 mm. in diameter. All the young of a 

 similar or somewhat larger size are ovoid or barrel-shaped, and, 

 besides being covered with a gossamer-like layer of prostal pent- 

 actins, show numerous, fine, needle-like (diactinic) prostalia 

 which spring singly from all parts of the external surface. Thus 

 the young are, in general appearance, scarcely distinguishable 

 from those of R. capillatus (PI. XXII., figs. 3-5). It seems the 

 diactinic prostalia lateralia are all lost during later stages of the 

 growth, though in some individuals similar proslals muy arise in 

 later life but in such cases they are restricted in their distribu- 

 tion to the oscular rim (marginalia). 



Spiculation. 



The parenchymalia principalia are bow-like oxydiactins with 

 tapering rays which subterminally are either smooth or sparsely 

 microtubercled. In large specimens they may attain 28 mm. in 

 length and 400 /^ in thickness at the middle ; such coarse spicules 

 occurring especially abundantly near the external surface in the 

 lower part of the body. The strength of the principalia of course 

 varies wâth the size of specimens. 



Close to the basal attachment I have found, abundantly in 

 one large specimen but not in the same proportion in others, 

 straight or bent parenchymal diactins, 8-15 mm. long and 20 /^ 

 thick on an average, in which the center is externally marked 

 by an annular swelling while one or both of the ends are swollen, 

 round-tipped and thickly beset with well-developed, conical micro- 



