PLATE XVII. 



PAGE 



Figs. 1-j. Holascus polejaevii, F. E. S., . . 89 



Fig. 1. Single specimen of Holascus polejaevii, F. E. S., preserved in alcoliol, 

 somewhat injured at the upper end ; natural size. 



Fig. 2. Section at right angles through the lateral wall (combination figure) ; 

 xlOO. 



Fig. 3. Oxyhexact from the trabecular framework ; x 300. 



Fig. 4. Oxyhexact with strong principal rays, from the trabecular framework ; 

 x300. 



Fig. 5. Hypodermal hexact with comital diacts, from the dermal skeleton ; 

 X 300. 



Figs. 6-8. Holascus ridleyi, F. E. S., . . . 90 



Fig. 6. Part of a principal tetract with comitalia ; x 300. 

 Fig. 7. Oxyhexaster with curved terminal rays ; x 300. 

 Fig. 8. Oxyhexaster with straight terminal rays ; x 300 



