DIFFLUGIA CURVIOAULIS. 31 



earlier work in having the mouth not in the least 

 dilated. The horn occupies an eccentric position ; it 

 makes the crown appear unsymmetrical ; and as well 

 as being inclined at an angle it is slightly incurved. 



Apart from the transparent siliceous scales little 

 extraneous matter is found adhering to the test of 

 D. curoicauUs. The individuals occurring in Sphagnum 

 seem to be less transparent than those inhabiting deep 

 water, for which, as well as other peculiarities, the 

 difference of habitat may sufficiently account. 



11. Difflugia lanceolata Penard. 

 (Plate XIX, figs. 9-11.) 



Difflugia pyriformis Leidy (pars) Fresliw. Rhiz. N. Amer. 

 (1879), p. 98, t. X, f. 17. 



Difflugia lanceolata Penard in Mem. Soo. G-eneve, XXXI 

 (1890), 2, p. 145, t. iv, ff. 59, 60; in Arch. Sci. nat. (3) 

 XXVI (1891), p. 143 ; and Faune Ehiz. Leman (1902), 

 p. 250, ff. 1-5 (p. 251) ; AvBEiNTZET in Trudui S.-Peterb. 

 Obshoh. „ XXXVI (1906) 2, p. 205; Schouteden in Ann. 

 Biol. Lacustre, I, 8 (1906), pp. 343, 347. 



Test thin, chitinous, transparent, with a covering of 

 siliceous angular scales, and sometimes, but sparingly, 

 minute sand-grains. Varying, within certain narrow 

 limits, in size and form ; ordinarily lanceolate from a 

 bluntly-acuminate or convex crown, swelling rapidly 

 to the greatest diameter, thence tapering convexly 

 down to the narrow truncated mouth ; the body of the 

 animal usually occupying about two-thirds of the test, 

 and attached to it by threads of ectoplasm. Pseudo- 

 podia few and simple, not branched ; nucleus spherical. 



Dimensions ; Length 140-160 ,u. y 



Ponds at Northenden, and elsewhere in Cheshire. 

 Loch Ness, Scotland {B. J. Scourfield). 



The test of this species is graceful in outline, and 

 may readily be distinguished from that of D. oblonga 

 var. lacnstris by the uniformly-convex sides and the 



