PLATE XV. 



PAGE 



Figs. 1-5. Holascus Jihulatus, F. E. S., . . .87 



Fig. 1 . Damaged fragment, inferior portion with the basal tuft ; natural size. 



Fig. 2. Fragment of the same specimen (fig. 1), inside; x 50. 



Fig. 'ia. Three-rayed spicule ; 36, c, d, two-rayed spicules or fibulae, from the 

 same specimen (fig. 1); x 500. 



Fig. 4. Middle part of a pentact from the same specimen (fig. 1); x 200. 



Fig. 5. Central fragment of a rosette, from the same specimen (fig. l); x 500. 



Figs. 6-13. Holascus stellatus,F. E. S., . . . 86 



Fig. 6. S^^ecimen, preserved in alcohol ; natural size. 



Fig. 7. Fragment of the same specimen (fig. 6), outside view ; x 50. 



Fig. 8. Part of a hypodermal hexact with a comital diact, from the same 

 specimen (fig. 6); x 200. 



Fig. 9. Oxyhexaster with curved terminal rays, from the same specimen (fig. 6); 

 x500. 



Fig. 10. Three-rayed spicule with bent rays and central node, from the same 

 specimen (fig. 6); x 500. 



Figs. 11, 12. Oxyhexasters of the specimen shown in fig. 6 ; x 500. 



Fig. 13. Inferior anchor-like end of spicule from the basal tuft of the specimen 

 shown in fig. 6. 



Figs. 14-23. Holascus sp., . . .86 



Fig. 14. Part of the wall of a specimen which was not in my hands; natural size. 



Fig. 15. Fragment of the outer portion of the wall of the specimen shown in 

 fig. 14; x50. 



Fig. 16. Part of a hypodermal hexact with a comital diact, from the specimen 

 shown in fig. 14 ; x 200. 



Fig. 17. Fragment of a discohexaster, from the specimen shown in fig. 14; x 500. 



Fig. 18. Fragment of a floricome-like discohexaster, from the specimen shown in 

 fig. 14 ; X 500. 



Fig. 19. Graphiohexaster from the specimen shown in fig. 14; x 500. 



Fig. 20. Discohexaster from the specimen shown in fig. 14 ; x 500. 



Fig. 21. Central part of a graphiohexaster, from the specimen shown in fig. 14 ; 

 x500. 



Fig. 22. Discohexact from the specimen shown in fig. 14 ; x 500. 



Fig. 23. Discohexaster from the specimen shown in fig. 14 ; x 500. 



This plate was arranged by Sir Wyville Thomson. 



