PSEUDODIFFLUGIA GRACILIS. 117 



The illustration by Archer in the ' Quart. Journ. 

 Micros. Sci.,' vol. ix, PL xx, fig. 1 {Pleurophrys ? 

 sphxrica) probably represents Pseaclodifiugia Archeri 

 as it measures 110 /x. in length. 



2. Pseudodifflugia fulva (Archer) Penard. 

 (Plate L, figs. 10-13; PL LI, fig. 12.) 



Pleurophrys fulva 



Archer in Qrt. Jrn. Mior. Sci. (n. s.) X (1870), pp. 20, 122, pi. xx, 



f. 3; op. cit. (N. s.) XIII (1873), p. 437 ; in Proc. Dubl. Micr. Club, 



I, 5 (1872), pp. 355, 390, pi. xiii, f. 3 ; op. cit. II, 3 (1876), p. 285. 

 SCHXTLZB in Arch. mikr. Anat. XI (1875), pp. 124-126, pi. vii, S. 2, 3. 

 Pseudodifflugia fulva 



Penard in Rev. Suisse Zool. IX (1901), p. 238 ; Paune Rhiz. Leman 



(1902), pp. 461-452, 5 figs. ; Sarcodines in Cat. Invert. Suisse (1905), 



p. 91. 

 HoPKiNSON in Irish Natur. 1910, pp. 3, 4. 

 Wailes in Scott. Natur. 1912, p. 61 ; in Jrn. Linn. Soc, Zool. XXXII 



(1912), p. 126; in Naturalist, 1913, p. 140. 

 Schmidt in Arch. Protist. XXIX (1913), pp. 219-220, pi. v, ff. 17-20. 



Test light brown or yellow in colour, small, pyriform,. 

 not compressed, covered with extraneous particles, 

 usually including a few large quartz-grains ; aperture 

 circular, terminal, devoid of neck ; nucleus placed pos- 

 teriorly, containing a single nucleole ; a single con- 

 tractile vesicle usually present ; plasma not entirely 

 filling the test; pseudopodia long, attenuate, numerous, 

 straight or branched. 



Length 15-30 jj,; diameter 12-20 /x; aperture 6-12 ju,. 



Habitat. — Aquatic vegetation. 



England. — N. Yorkshire; Rutlandshire; Bucking- 

 hamshire ; Hampshire ; Isle of Wight ; Devonshire ; 

 Cornwall ; Scilly Isles. 



Scotland. — Outer Hebrides. 



Ireland. — Clare Island and Caher Island, Mayo ; 

 Inishbofin, G-alway; "Wicklow (Archer). 



Probably distributed generally in the British Isles, 

 but owing to its small size this species is easily over- 

 looked. Penard gives 15 to 23 /a as the usual limits of 

 length; Archer's figure measures about 30 ju. ; in the 



