io6 Brown : Freshivafer Rhizopods . 



pellicle. Amongst the moss\^ growth on the over-flow of water- 

 troughs. Ecclesall, etc. 



Amoeba Umax Dujardin. A small form. Occurs in sedi- 

 ment of pools. Ringinglow and Ecclesall Woods. 



Amoeba limicola Rhumbler. Occasionally found in sedi- 

 ment of pools. Ringinglow. 



Amoeba verrucosa Ehrenb. A form with external pellicle. 

 According to Penard, a collective term for several distinct 

 species. Amongst mossy vegetation. Ecclesall and Bamford. 



Amoeba adinophora Auerbach. A very small species, but 

 highly interesting. Occasionally in sediment. Whiteley Woods 

 and Ecclesall. 



Dactylosphaerium radiosum (Ehrenb) Biitschli. A small form 

 occurs in sediment (Ringinglow) and amongst floating conferva 

 (Wye at Haddon), etc. 



Family Vampyrellida. 



Vampyrella lateritia (Fresen.) Leidy. A peculiar form 

 parasitic on AlgcB. Burbage. 



Vampyrella vorax Cienkowski. A non-parasitic and active 

 species, feeding on Diatoms, etc. Amongst mossy growth on 

 w^ater-troughs. Ecclesall. 



Order 2. — Conchulina. Forms provided with tests. 

 Family Arcellida. 



Arcella vulgaris Ehrenb. A very common species amongst 

 aquatic vegetation. 



Var. compressa Cash is rare. Occurs in Sphagnum pools, 

 Ringinglow. 



Arcella discoides Ehrenb. Amongst Sphagnum. Ringing- 

 low and Stanage. 



Pseudochlamys patella Clap, et Lachm. A curious form 

 with very delicate flexible test. Occurs on dripping rocks 

 amongst moss at Slippery Stones (Derwent). Mid-winter. 



C entropy xis aculeata (Ehrenb.) Stein. Common amongst 

 sphagnum and in pools. 



Var. ecornis (Ehrenb.) Leidy, generally with the above. 



Difflugia pyriformis Perty. Common in pools, troughs, and 

 amongst aquatic vegetation. Very variable. 



Var. compressa (Carter) Leidy. Fairly common in similar 

 situations. Stanage, Froggatt, etc. 



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