DIFFLUGIA GLOBULUS. 35 



HEIM in Forh. Geol. Foren. Stockholm, XXIII (1901), p. 

 511 etc.; Gr. S. WEST in Jrn. Linn. Soc., Zool. XXVIII 

 (1901), p. 324; and in Ann. Scott. Nat. Hist. 1906, pp. 

 90, 92 ; BEARDSLEY in Tr. Amer. Micr. Soc. XXIII (1902), 

 p. 57 ; KOPOID in Bull. Illinois State Lab. VI, 1 (1903), 

 p. 516; ZYKOFF in Bull. Soc. Nat. Moscou, XVII (1903), 

 1, pp. 15, 107; MURRAY in Pr. R. Soc. Edinb. XXV, 8 

 (1905), p. 614; and in Ann. Scott. Nat. Hist. 1907, p. 94 ; 

 CCSHMANN in Amer. Natur. XL (1906), p. 372; SCHORLER 

 & THALLWITZ in Ann. Biol. Lacustre, I, 2 (1906), p. 270 

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

 343, 347 ; THIEBAUD & FAVRE in Ann. Biol. Lacustre, I, 1 

 (1906), p. 76 etc. ; and in Zool. Anzeig. XXX (1906), p. 

 156 ; LEMMERMANN in Arch. Hydrobiol. II, 4 (1907), p. 

 537 ; SCHNEIDER in Arch. Biontol. II (1908), 1, p. 58. 

 Difflugia globosa GOLDSMIDT in Arch. Protist. V, 1 (1904), 

 p. 131. 



Test ordinarily globular or hemispherical, but sub- 

 ject to variation, truncated on the broad ventral 

 surface ; composed of chitinous membrane, with an 

 incrustation of sand-grains or diatom-frustules, or 

 both of these ; the mouth circular, its margins not 

 invaginated, often large proportionately to the size of 

 the structure. Protoplasm colourless, containing 

 chlorophyllous food-particles and a single nucleus ; 

 pseudopodia single, blunt, few in number. 



Dimensions : 15-50/x, or more in longest diameter. 



In the ooze of ponds ; in marshes and amongst 

 Sphagnum and other mosses in moist places ; common. 



A good deal of confusion has arisen with regard to 

 this species. The name globulosa was given by 

 Dujardin (1837) to a testaceous rhizopod palpably 

 different from that to which, since his time, it has 

 been applied by authors. Dujardin's figure represents 

 a smooth-surfaced apparently chitinoid test, semi- 

 opaque, ovoid in lateral, and elliptic in dorsal view, 

 with the mouth a very small, circular orifice situated 

 at the narrow extremity, with the blunt, digitate, and 

 sometimes branched bifurcate pseudopodia issuing 

 from it. We are unable to correlate Dujardin's 



