ACTINOPODOUS HOLOTHUKIOIDEA. 



19: 



Calcareous ring is well developed (textfig. 36a). When looked 

 at from the outside, it looks simply like a plain ring with some 

 mdentations, but when it is pulled outward so as to show the in- 

 side a httle, processes become visible. Polian vesicle one, on the 

 left ventral interradius of the circular canal. Genital organs 

 two, bushy, one on each side of the dorsal mesenterv. Genital 

 papilla distinct in the median dorsal line. The stone-canal opens 

 with several openings near the base of tlie genital papilla. 



Calcareous deposits are as pointed out by Thi^el, comprising 

 large wheels, small wheels, cruciform bodies, and spinose spicules! 

 Large wheels are largest in dorsal papilla?, 0.180—0.220 mm. in 

 diameter, with eight or rarely nine spokes and four central holes 

 (h) ; those in lateral pedicels, 0.120-0.164 mm. In dorsal and 



'^(K^WM^'^UU^ 



Textfig. 36. 



_ Lairnorjone violacé,: «-Calcareous ring; ^,-Large ^.heel of dorsal papula: o-Middle- 

 .zed wheel of dorsal pen-some; ./-Small wheel of dor.nl papilla; c-Spino.xs spluleof 

 cor^alpensome /-Cr..ciform body of ventral perisome ; .-Supporting rod^ofoLTapHI^ 

 /.-Spinous rod from genital tubes. (/.-Ax 200). I-Interradialia ; R_Eadialia. 



ventral perisome, large wheels are few and scattered, cruciform 

 bodies being most numerous. The large wheels are relativelv 



