PLATE XIX. 



Figs. 



1, 2. Diffiugia ohlonga var. lacustris (Penard) Cash. (p. 12) 

 Typical forms from ponds at Northeiiden, Cheshire. 

 X 280. 

 3, 4. D. ohlonga Bhrenb. (p. 4) Two forms of test in 



Sphagnum from Dunham, Cheshire. x 280. 

 5-7. D. petricola Cash. (p. 18) Figs. 5, 6. — Lateral and 

 oral views of an empty test. Fig. 7. — A peculiar 

 double test formed of aggregated sand-grains, with 

 two apertures. Dunham Marsh, x 280. 

 8. (?) D. curvicaulis Penard. (p. 29) In Sphagnum from 

 Criccieth, August, 1904. x 280. 

 9-11. D. lanceolata Penard. (p. 31) Examples showing 

 variation in form and size ; from Cheshire ponds. 

 X 280. 

 12, 13. D. brevicoUa Cash. (p. 38) Fig. 12.— Oral view of 

 an empty test. Fig. 13. — Two individuals in conju- 

 gation. From a peat-moss near Warrington, x 280. 

 14-20. D. constricta (Ehrenb.) Leid3^ (p. 54) Various forms 

 more or less common in ponds and amongst Sphag- 

 ■iium. Fig. 17. — A spined form. From Danham. 

 Fig. 18. — A large form in Sphagnum from Tan-y- 

 Bwlch, June, 1908. Figs. 19, 20. — Lateral and front 

 views of an empty test. Dunham, 1904. x from 

 300 to 360. 



