74 BRITISH FRESHWATER RHIZOPODA. 



described by Leidy and others as forms of Difflugia 

 globulus. Whilst possessing a close resemblance in 

 the structure of the test, they differ from that species 

 in the character of the pseudopodia, "which, in their 

 ultimate extremities, are pointed, not blunt. 



1. Phryganella acropodia (Hertwig & Lesser).* 

 (Plate XX, figs. 13 and 14.) 



Difflugia acropodia Heetwig & Lessee in Arch. mikr. Anat. 



X (1874), Suppl. p. 107, t. ii, f. 6; Aechee in Q. Jrn. 



Micr. Sci. XXVII (1877), p. 114; and in Jrn. Dublin 



Micr. Club, III, 2 (1877), p. 232. 

 Difflugia glohulosa Leidy (pars) Freshw. Ehiz. N. Amer. 



(1879), p. 96, t. xvi, ff. 23, 24. 

 Pseudodifflugia hemisph erica Penaed in Mem. Soc. Geneve, 



XXXI (1890), 2, p. 169, t. vii, ff. 108-114. 

 Phryganella hemispheric a Penaed Faune Ehiz. Leman 



(1902), p. 421, ff. 1-5 ; in Arch. Protist. II (1908), p. 264; 



and in Jrn. R. Micr. Soc. 1907, p. 278; Avkejntzev in 



Trudui S.-Peterb. Obshch. XXXVI (1906), 2, p. 261 ; 



ScHOUTEDEN in Ann. Biol. Lacustre, I, 3 (1906), p. 360. 



Test hemispherical in side view, yellowish or 

 brownish, semi-transparent, and covered with amor- 

 phous scales, and sometimes sparsely with sand- 

 grains ; viewed ventrally circular in outline, the 

 mouth occupying about two-thirds of the area, and 

 concentric ; nearly always (in the living state) sur- 

 rounded by flocculent material to a considerable 

 extent obscuring the mouth which is sometimes sur- 

 rounded by a ring of comparatively large sand-grains. 

 Tlie ectoplasm emerges from the oral aperture often in 

 ribbon-like masses, which divide at their extremities 

 into sharply-cut prolongations of variable length 

 extending radially on all sides when the animal is in 

 active movement. Bndoplasni colourless, containing 

 a single nucleus and a variable number of chlorophyll 

 and other particles. 



Dimensions : Diameter 30-50 ju,. 



* [Phryffanella hemispherica Penard ; Cash, MS.] 



