RHIZOPODS FROM THE SHEFFIELD DISTRICT.*^' 



JAMES M. BROWN, B.Sc, 

 Sheffield. 



In a previous number of 'The Naturalist ' (March 1909), I 

 gave a Hst of the Freshwater Rhizopods which I had collected 

 in this district up to that date. Since then continued work 

 has made known the occurrence of nearly thirty further species. 

 While some of these are fairly well-known forms, others appear 

 to be little known, or at any rate have been seldom noticed, 

 while a few are, I believe, new to this country. 



I give in each case a reference to the authority, so that 

 other naturalists may easily refer to the original descriptions 

 of the species. 



i.~Amoeha fiuida Griiber (' Zeitschr. f. wiss. ZooL' Bd. 41, 

 1885 ; Penard : ' Faune rhizopodique du Bassin du Leman,' 

 1902, p. 42). A fairly large form of the ' limax ' type, which 

 shows peculiar internal currents in the protoplasm. ^ Occurs in 

 sediment from Burbage. Size loo//. Rare. 



2.~-Amoeba vespeyiilio Penard. (' Faune rhizop,' p. 92). 

 An occasional form met with in sediment and characterised 

 specially by the triangular and pointed shape of the pseudopodia. 

 r^ound also in Esthwaite Lake. Size 50 /x. 



^.—Amoeba terricola Greeff. (' Arch. f. mikr. Anat.' Bd. II., 

 1866, p. 299). In my previous paper I mentioned that A. 

 verrucosa Ehr. was probably a composite species, now broken 

 up into distinct species. A . terricola is one of these and the most 

 commonly occurring form. It is widely distributed amongst 

 mosses, both submerged and growing in woods, on walls, etc. 



4.— Amoeba papyracea Penard. (' Arch. f. Protistenk,' 

 1905, p. 201). A pellicled form like the last, and occurring in 

 similar situations but not so common. Found in numbers 

 amongst Lichen, Wyming Brook. 



S-~Ouramoeba vorax Leidy (' Freshwater Rhizopods of 

 North America,' 1879). Occasionally Amoebae occur which 

 are attacked by parasitic fungi which produce tufts of hyphal 

 filaments protruding from the surface of the animal. To such, 

 Leidy gave the name ' Oiiramoeba: Various species are attacked 

 in this way. In sediment at Burbage, numerous A. villosa 

 occurred, most being attacked by the fungus. 



6. — Hyalodiscus rnbicundus H. and L. (' Arch. f. mikr. 

 Anat,' Vol. X ., suppl. ; Penard, Faune rhizop., p. 159; Cash. 



* ^ Qr previous paper see ' Naturalist,' March, 1909, pp. 105-108. 

 1910 Feb. I. 



