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EXPLANATION OF PLATE VI. 



Fig. 1. A side view of Thaumantias, natural size. 

 b. View from beneath. 



The lips and part of peduncle. 



A pair of tentacles, with an intermediate marginal vesicle. 



One of the ovaries. 



Do., immature. 



Section of tentacular bulb lined with glandular cells. 



Do., showing the respective positions of the tentacular bulbs and marginal 

 vesicles to the marginal canal. 

 Fig. 8. a. Rudimentary tentacular bulb. 



b. Marginal vesicle. 



c. Tentacle and bulb. 



Fig. 9. Another view of tentacular bulb and its sometimes infundibuliform cavity. 

 Fig. 10. Incipient tentacular bulb. 



a. Upper wall of marginal canal, becoming thickened. 



b. Marginal vesicle. 



c. Lower wall of marginal canal, thickened, and thickly beset with fili- 



ferous vesicles. 

 Fig. 11. Highly magnified transverse sectional view of tentacular bulb. 

 Fig. 12. A marginal vesicle with a solitary lens. 

 Fig. 13. Do., with four lenses. 

 Fig. 14. A more highly magnified view of a marginal vesicle with one lens, and 



smaller spherical bodies having a double contour. 

 Fig. 1 5. A view of a marginal vesicle magnified with a power of 450 linear, and 



under polarized light ; showing the black cross formed by the lens, and 



an indistinct granular appearance in the chamber in which it is lodged. 



This space under ordinary light appears quite transparent and clear. 



A vitreous humour ? 

 Fig. 16. a. Filiferous vesicles imbedded in incipient tentacular bulb. 



b. Others detached and more highly magnified. 



c. One with the filament and neck-like process extruded. 



d. A portion of the muscular expansion of the subumbrella. 



