PLATE XVII. 



Pigs. 

 1-3 a. Difflugia ohlonga Elirenb. (p. 4) Figs. 1, 2. — Forms 

 commonly met with in ponds, x 200. Fig. 3. — 

 Large form, with a comparatively smooth test^ from 

 a pond at Chipperfield, Herts, x 160. Fig. 3 a. — 

 Pseudopodia of the same when emitted after ix'rita- 

 tion. X 160. 

 4, 5. D. ohlonga var. venusta (Penard) Cash. (p. 10) Forms 

 varying in shape and size. Northenden, Cheshire. 

 X 280. 

 6. D. iiblonga var. claviformis (Penard) Cash. (p. 11) 

 Large form, from pond at Chipperfield, Herts. x 

 160. 

 7,8. X). ohlonga Blirenb. (p. 7) Fig. 7. — A very small 

 form, with tubular neck, from pond at Chelford, 

 Cheshire. Fig. 8. — A fi.rm with a mamillary pro- 

 tuberance on the crown, otherwise agreeing with the 

 type. Pond at Northenden, Cheshire, x 280. 

 9. D. ohlonga var. clavifor'nns ? A form varying in the 

 character of the crown, from pond at Chipperfield. 

 X 160. 



