Plate XX. 



lÜtabdocalyptufi 'mollis F. E. tScH. P. 253. 



P'ig. I. A s})ecimeu (0. C. No. 103) well preserved, exce[>t in that a 



bud has been torn off. ^ natural size. 

 Fig. 2. A specimen (8. C. M. No. 420) iVoni which a triangular piece of 



the wall had been cut away. ^ natural size. (Figs. 3-9 were 



all taken from this specimen). 

 Fig. 3. A normal oxyhexaster from the subdermal sjjace. 300 x . 

 Fig. 4, Microdiscohexaster. 300 x . 

 Fig. 5. ]3iscoctaster. 300 x . 

 Fig. 6. A hemihexactinose oxyhexaster with 10 terminals in all, from 



deep parts, 300 x . 

 Fig. 7. A liexactinose oxyhexaster; two of the straight rays each showing 



at base the remnant of an atrophied terminal in the form of a 



unilateral spine. 300 x . 

 Fig. 8. A quite liexactinose oxyhexaster. 300 x . 

 FiiX. Î). Another liexactinose oxvhexaster with all the ravs crooked at 



base. 300 x . 

 Fig. 10. A nearly hexactinose oxyhexaster ; one of the rays is simply bent 



at base, while another similarly l)ent ray shows the rudiment ol' 



a fellow terminal belonging to the same ])rincipal. From 0. C. 



No. 104. 300 X. 

 Fig. LI. A hemihexactinose oxyhexaster with very strongly developed basal 



barbs to the rays. From 0. C. No. 104. 300 x . 

 Fig. 12. »Spicules of ectosome seen in surface view. From ß. C. M. No. 



420. 30 X . 

 Fig. 13. Spicules of endosoiiie seen in surface view. From S. C. M. N(j. 



420. 30 X . 



