DIFFLUGIA UKCEOLATA. 41 



(1906), pp. 344, 348; THIEBAUD in Zool. Anzeig. XXX 

 (1906), p. 156 ; THIEBAUD & FAVRE in Ann. Biol. Lacustre, 

 I, 1 (1906), p. 76 etc.; HOOGKNRAAD in Tydschr. Nederl. 

 Dierk. Ver. (2) X (1908), p. 407; LANDACRE inPr. Daven- 

 port Acad. Sci. IV, 10 (1908), p. 428. 



Difflugia proteiformis sub-sp. mitriformis var. lageniformis 

 WALLICH in Aim. Nat. Hist. (3) XIII (1864), p. 240, t. 

 xvi, ff. 15, 16. 



Difflugia lageniformis BUTSCHLI in Bronn's Thier-Reichs, I, 

 1 (1880), t. iii, f. 8. 



Test ovoid, rotund, its crown obtusely and evenly 

 rounded, plain, or furnished with one or more short 

 bluntly-conical protuberances ; the neck short, con- 

 stricted above the wide circular mouth, which has an 



FIG. 56. Typical form of Difflugia urceolata. From Richmond Park, 

 Surrey, x about 180. 



expanded and slightly-recurved rim, its basal outline 

 being straight or convex. Body of the test, as well as 

 the expanded mouth, incrusted with quartzose sand- 

 grains and other opaque material. The plasma pluri- 

 nuclear, colourless ; the pseudopodia digitate, simple 

 or branching, generally numerous. 



Dimensions : Length 220-230 /x; breadth 150-200 p. 



In ponds and ditches, not common. Eichmond Park, 

 Surrey. Chipperfield, Herts (A. Earland). BoAvness, 

 Westmoreland (G. 8. West). Loch Ness, Scotland 

 (D. J. Scourfield). 



D. urceolata is one of the largest of our native 

 Diffluyise. Though widely distributed in Europe and 

 America, it is not abundant in England. Both the 

 spined and spineless forms, however, occur in different 

 parts of this country. The test is opaque, and with- 



