12 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



4. Without contractile vacuole Protamocha?\ 



With contractile vacuole Gloidmm?\ 



5. One pseudopodium directed forwards Hyalodiscus* 



Pseudopodia more than one 6 



6. Pseudopodia finger-like, from the border only, or 



from one or few parts of the spherical body 7 



Pseudopodia various but from all sides of the body . . 8 



7. Discoidal ; pseudopodia radiating from all sides .... 



Dactylosphccrium 

 Spherical ; pseudopodia from one spot ; commonly 

 violet Amphizonclla 



8. Pseudopodia many, lobe-like, from all sides of the 



body Amocha* 



Pseudopodia many, fine, membrane-like ; ectosarc 



reddish Plakopus 



Pseudopodia few, very broad ; animals large 



Pelomyxa* 



9., Pseudopodia finger-like 10 



Pseudopodia thread-like 18 



10. Shell chitinous, colorless or yellowish, with a struc- 



ture only visible w'ith high powers 1 1 



Shell with evident structure, either secreted by the 



animal or made of foreign bodies 15 



11. Shell watch-glass shape; pseudopod opening on 



under side 12 



Shell ellipsoidal, compressed, structureless Hyalosphenia 



12. Shell hyaline 13 



Shell showing hexagonal markings 14 



13. Pseudopod opening large, not closed by a mem- 



brane ; pseudopods many Cochli op odium 



Pseudopod opening closed by a membrane as far as 



the pseudopodia; shell flexible Pseudochlamys 



Pseudopod opening narrow'ed by an evident border 



Pyxidicida 



14. With a variable number of spines Cen fro pyxis* 



Without spines ; shell yellow or brown Arcella* 



15. Shell made of sand grains, diatom shells, etc 



DifHugia* 



* Genera already found in Connecticut and described in the following pages. 

 J- Doubtful genera. 



