260 Mr. H. J. Carter on Filigerous Green Infusoria. 



The same doubt exists here with respect to Halteria pulex 

 that accompanies the observation of many Infusoria, viz. whe- 

 ther or not it be the adult form of the animalcule which it 

 represents. The presence, as before stated, of true generative 

 elements can only decide the question. Until this be deter- 

 mined, all that can be said of Halteria pulex is that its form 

 and habits are strikingly like those of a young podophryan 

 Acineta. 



EXPLANATION OF PLATE XVII. figs. 10-24. 



N.B. All the figures in this Plate are drawn upon the scale of l-12th 

 to 1 -5400th of an inch, unless where otherwise mentioned. 



Fig. 10. Euglena tuba, n. sp. Portion of the encysted, passive, or still 

 state, forming a red crust on the surface of the water : a, Eu- 

 glence; b, trumpet-shaped cysts; c, general investing mem- 

 brane. (Scale l-24th to l-5400th of an inch.) Some of the 

 cysts have not been coloured, and the trumpet-shape tube is not 

 added in all, for convenience. 



Fig. 11. The same, more magnified, encysted : a, trumpet-shaped elonga- 

 tion of the cyst. 



Fig. 12. The same, empty cyst. 



Fig. 13. The same, in active state. 



Fig. 14. Uvella both, Ehr. The 16-cell form : a, cell bearing eye-spot 

 and contracting vesicle ; b, dotted line showing axial cavity round 

 which the cells individually are fixed ; c, cilia ; d, separate cell, 

 showing red eye-spot, contracting vesicle, and single cilium ; 

 e, individual cell belonging to a group where the cilium floated 

 backwards. 



Fig. 15. The same, 32-cell form, still within the cell- wall of the parent : 

 a, caudal prolongation. 



Fig. 16. Glenoclosterium varians, nov. gen. et sp. : a, red eye-spot ; b, nu- 

 cleus ; c, starch-utricles surrounded by chlorophyll, as in Clos- 

 terium and the bands of Spirogyra. 



Fig. 17. The same (?), with the body more confined to the centre of the 

 cell (approaching the form of Chlamydococcus) : a, red eye-spot. 



Fig. 18. The same (?), assuming a spicular form ; no eye-spot. Filled with 

 chlorophyll and transparent vesicles attached to amylaceous (?) 

 granules. 



Fig. 19. The same, with bifid extremity. 



Fig. 20. The same, of a sigmoid form, with central utricles, but no eye- 

 spot. 



Fig. 21. The same, with a pointed conical extension of the cell on one 

 side only. 



Fig. 22. Chlamydococcus ? (active state), of which figs. 16-21 inclu- 

 sive appear to be passive states. 



Fig. 23. Halteria pulex, Clap, et Lach. : a, frill of propelling cilia ; b, re- 

 tractile cilia; cc, contracting vesicles. (Scale l-6th to 1 -5400th 

 of an inch.) 



Fig. 24. Primary active cell (sporozoid) of Eudorina elegans : a, red eye- 

 spot ; b, contracting vesicles ; c, nucleus. 



