56 BRITISH FRESHWATER RHIZOPODA. 



Plon, I (1893), p. 3; and op. cit. II (1894), p. 57; 

 ZSCHOKKE in Verh. nat. Ges. Basel, XI, 1 (1895), p. 59 

 etc.; DADAY in Termesz. Fuzetek, XX (1897), p. 153; 

 and op. cit. XXI (1898), Suppl. pp. 5, 9; FRANCE in Res. 

 wiss. Erforsch. Balatons. II (1897), 1, pp. 3, 8 ; FRENZEL 

 in Bibl. Zool. IV, 12 (1897), p. 148, t. ix, f. 7; FDHR- 

 MANN in Rev. Suisse Zool. IV (1897), p. 494 etc.; SCHAU- 

 DINN in Deutsch-Ost- Africa, IV, 2 (1897), 19, p. 9; 

 SCOURFIELD in Pr. Zool. Soc. 1897, p. 787; ANDRE in 

 Jahresb. nat. Ges. Graubiind. XLI (1898), p. 57 etc.; 

 STENROOS in Acta Soc. Fauna Feiin. XVII (1898), 1, pp. 35, 

 81; AVERINTZEV in Trudui S.-Peterb. Obshch. XXX, 1 

 (1900), p. 209 ; op. cit. XXXVI (1906), 2, p. 216 ; in Ber. 

 Siisswass. nat. Ges. St. Petersb. I (1901), p. 212; and in 

 Zool. Anzeig. XXXI (1907), pp. 244, 309 ; EYFERTH Natur- 

 gescb. mikr. Siisswass. ed. 3 (1900), p. 263 ; GODET in Bull. 

 Soc. Neuchatel, XXVIII (1900), p. 77; LAGERHEIM in Forh. 

 Geol.Foren. Stockholm, XXIII, 6 (1901), p. 510 etc.; and 

 op. cit. XXIV (1902), p. 246 etc. ; G. S. WEST in Jrn. Linn. 

 Soc., Zool. XXVIII (1901), p. 317 ; and in Ann. Scott. Nat. 

 Hist. 1905, p. 89; BEARDSLEY in Tr. Amer. Micr. Soc. 

 XXIII (1902), p. 57; KOFOID in Bull. Illinois State Lab. 

 VI, 2 (1903), p. 526; ZYKOFF in Bull. Soc. Nat. Moscou, 

 XVII (1903), p. 16 ; FOREL Le Leinan, III (1904), p. 138 ; 

 CUSHMAN in Amer. Natur. XL (1906), p. 172; EDMONSTON 

 in Pr. Davenport Acad. Sci.XI (1906), p. 14, t. iii, f. 14 ; 

 SCHORLER & THALLWITZ in Ann. Biol. Lacustre, I, 2 (1906), 

 p. 260; SCHOUTEDEN in Ann. Biol. Lacustre, I, 3 (1906), pp. 

 340, 348; THIEBAOD in Zool. Anzeig. XXIX (1906), p. 796; 

 MURRAY in Ann. Scott. Nat. Hist. (1907), p. 94 ; LE Rocx 

 in Ann. Biol. Lacustre, II, 1 (1907), p. 264; ZSCHOKKE in 

 Arch. Hydrobiol. II (1907), 1, p. 4; SCHNEIDER in Arch. 

 Biontol. II, 1 (1908), p. 58. 



Difflugia marsupiformis BUTSCHLI in Bronn's Thier-Reichs, 

 I, 1 (1880), t. iii, ff. 2, 3; PENARD in Jahrb. nassau. Ver. 

 Naturk. XLIII (1890), p. 70; and in Rev. Suisse Zool. 

 XXXI (1890), 2, p. 143, t. iv, ff. 30-33; LAGERHEIM in 

 Forh. Geol. Foren. Stockholm, XXIII (1901), p. 512. 



Difflugia (Arcella] constricta CERTES in Mission scient. Cap. 

 Horn, VI, 3 (1889), p. 13. 



Difflugia platystoma PENARD in Rev. Suisse Zool. XXXI 

 (1890), 2, p. 143, t. iv, ff. 35-37. 



Test very variable in size and form, distinguished 

 from other species by its antero-inferior mouth, the 



