EXPLANATION OF PLATE IX. 

 Figs. 1-10. Holascus rohustus. F. E. Sch. 



Fig. 1. Arrangement of the spicules in a transverse section of tlie body- 

 wall. The upper margin corresponds to the dermal surface. x 80 (combined 

 figure). 



Fig. 2. Simple parenchymal micro-oxyhexactine. x 400. 



Fig. 3. Hemioxyhexaster with only one branched main-ray. x 400. 



Fig. 4. Hemioxyhexaster, most of the main-rays of which are branched. 

 X 400. 



Fig. 5. Oxyhexaster with slender main- and branch-rays, x 400. 



Fig. 6. Lower part of a basal anchor-spicule. x 250. 



Fig. 7. Calicocom. x 400. 



Fig. la. Central part of a graphiocom, the branch-rays of which have 

 been broken off. x 400. 



Fig. 8. Central part of a macrosclere stauractine. x 100. 



Figs. 9 and 10. Parts of long triactine comitalia. x 20. 



Figs. 11-14. Lijusaciiies. 



Fig. 11. Part of basal prostal. x 100. 



Figs. 12-13. Tuberculous silica-pearls. x 100. 



Fig. 14. Larger, smooth silica-pearl. x 100. 



