Plate X. 



Agaricoides alcocki, Simpson, n. g. et sp. 



Fig. 1. Typical colony nat. size. 



,, 2. Zooid enlarged ( x 10). 



,, 3. Young colony (nat. size) showing first stage in the development of the 

 verruca. 



,, 4. Enlarged polyi^ and stem canal showing the method of growth. 



,, 5. Vertical section through a colony to show the relations of the parts 

 (nat. size). 



„ 6. Enlarged section of one of the stem canals ( x GO). 



,, 7. Asulcar filament enlarged ( x 80). 



,, 8. Cross section through the introverted authocodia ( x 30). 



„ 9. Vertical section through a verruca and stem canal with the zooid intro- 

 verted (x 10). 



,, 10. Pale yellow spicules of the an thocodia. 



., 11. Enlarged section through the stomodajum showing the sulcus ( x 70). 



,, 12. Transparent spicules of the partition walls. 



„ 13. Transparent spicules of the outer wall of the trunk. 



,, 14. Transparent and pale yellow spicules of the verruca-disc. 



,, 15. S|3icule enlarged ( x 490) to show the organic axis. 



,, 16. Surface view of a verruca-disc, the zooid being introverted ( x 7). 



., 17. Enlarged section through a wall showing the spicule cavities and the 

 residue of the organic axis ( x 15). 



,, 18. Pale yellow spicules of the tentacles. 



,, 19. Section through the trunk showing the mesenterial filaments passing into 

 the stem canals ( x GO). 



