DIFFLUGIA OBLONGA. / 



109 ; Andee in Jahresb. nat. Ges. Grraubiind. XLI (1898), 

 p. 57 etc. ; Penaed in Rev. Suisse Zool. XIII, 3 (1905), 

 p. 596, t. xiii, ff. 12-14; and op. cit. XVI, 3 (1908), p. 

 402 etc. ; Mukeay in Ann. Scott. Nat. Hist. 1907, p. 94. 

 Difflugia oblongata Butlbe in Handb. Dublin (Brit. Assoc. 

 1908), p. 219. 



Test variable in outline and in size ; typically oblong 

 or pear-shaped; symmetrical, whether viewed longi- 

 tudinally or transversely ; the crown arched, sometimes 

 furnished with a mamillary protuberance (PI. XVII, 

 fig. 8), the sides tapering with more or less convexity 



Fia. 36. — Di#tt9ia oblonga : a-d, different aspects of test and states of 

 activity of pseudopodia of the same individual. After Ehrenberg-, 

 loc. cit. (reduced), x 200. 



to the truncated mouth, or narrowed suddenly so as to 

 form a short cylindrical neck. The surface incrusted 

 with opaque sand-grains. The protoplasm granular, 

 colourless, with a single nucleus in the posterior region, 

 and three to six digitate, blunt, simple or sparingly- 

 branched pseudopodia. 



Dimensions : Length from about 100 /x, to 300 /a, or 

 more ; breadth 50-100 /x. 



In the ooze of ponds, on the submerged stems and 

 leaves of aquatic plants, and amongst the vegetation in 

 swamps and marshy places ; common and universally 

 distributed. 



