DIFFLUGIA PETRICOLA. 19 



grains which give it a rugged outline, the neck only 

 being composed of fine particles and comparatively 

 smooth. Neck tubular and slightly contracted at the 

 mouth which has a sharply-defined outline. 



Dimensions : Diameter of test about 80 p ; length of 

 neck 25-30 ja, its width 20 /*. 



In Dunham Marsh, Cheshire, amongst Sphagnum 

 and other mosses in very wet ground, 1903. 



This is so distinct a form, and apparently so little 

 subject to variation, that one has little difficulty in 

 claiming it as a species. In the autumn of 1903 empty 

 tests occurred abundantly in squeezings of Sphagnum 

 and other sub-aquatic mosses which had been kept too 

 long before examination. Living examples were not 

 found, and the organism up to the time of writing has 

 not since been met with. 



The incrustation of the tests was extraordinary ; 

 large angular sand-grains were agglutinated together 

 so that each test was more heavily weighted than is 

 usual with Diffiugise ; and they were quite opaque. 

 The finely-moulded short neck was characteristic ; no 

 other species has one quite like it. A unique example 

 was observed of a double test, as though an individual 

 had annexed its neighbour, producing a form which 

 looked like a test with two necks and two apertures. 



This singular Difflugia occurred in spongy ground 

 overgrown with mosses and other vegetation amongst 

 which was abundance of Utricularia minor. Associated 

 with it was Lesquereusia insequcdis sp. nov. and L. 

 epistomiu in Pen ar d . 



8. Difflugia acuminata Ehrenberg. 



(Plate XVIII, figs. 12 and 13; and figs. 34 and 42-44 



in text.) 



Difflugia acuminata EHRENBERG Infusioiisth. (1838), p. 131, 

 t. ix, f. 3; DUJARDIN Infus. (1842), p. 249, f. 5; PRITCHARD 

 Hist, Infus. (1842), p. 168; ed. 4 (1861), p. 553; PBRTY 

 Kenntn. kleinst. Lebensf. (1852), p. 187 ; COLE in Pr. 



