144 BRITISH FRESHWATER RHIZOPODA. 



and in Zool. Anzeig. XXXI (1907), p. 310; G. S. WEST 

 in Jrn. Linn. Soc., Zool. XXVIII (1901), p. 323; SCHOU- 

 TEDEN in Ann. Biol. Lacnstre, I, 3 (1906), p. 357; LANDACEE 

 in Pr. Ohio Acad. Sci. IV, 10 (1908), p. 429. 



Test large, broadly ovoid, strongly compressed, com- 

 posed of chitinous membrane (yellowish or brownish- 

 tinted) with a surfacing of amorphous transparent 

 scales ; the crown forming a broad semi-circle and 

 rough with sand-grains, the lateral margins convex 

 and carried with an unbroken outline round the slightly 

 narrowed basal extremity ; the mouth, consisting of a 

 narrow slit, extending from side to side, its extremities 

 taking in some examples an upward turn, so as, in 

 narrow lateral view, to form an acute notch w T ith the 

 lips closely approximating. In transverse view (the 

 crown being presented to the eye) the test is bi-convex. 

 A considerable part of its cavity is unoccupied by the 

 living organism. This in some individuals is concen- 

 trated in the upper half of the test, consisting of a 

 round ball, with a distinct neck extending downwards 

 to near the mouth where it widens out and occupies 

 the extent of the narrowly-elliptic aperture, giving off 

 generally a considerable group of thinnish and some- 

 times branching pseudopodia. In other examples (as 

 in some gathered near Towyn) the plasma is connected 

 with the internal walls of the test by prolongations of 

 its own substance. It is not infrequently crowded 

 with chlorophyllous pellets, clear vacuoles, and dense 

 granular material, which more or less obscure the 

 large nucleus; and a contractile vacuole may generally 

 be detected in the anterior part of the endoplasm. 



Dimensions: Length 145 /t; breadth 120 /A; across 

 the mouth (in the Towyn examples), between the two 

 extremities, 80 /A; breadth in dorsal view, 50 p. 



In Sphagnum, Knutsford Moor, Cheshire; in tufts 

 of Hypnum Jiuitans from boggy ground at Dunham, 

 Cheshire; also in similar situations on Irlam Moss, 

 Lancashire ; Llyn Idwal and near Towyn, N. Wales. 

 Epping Forest, Essex (D. J. Scourfield). 



