40 BRITISH FRESHWATER RHIZOPODA. 
truncate ; aperture hexagonal or lobed, of medium size, 
bordered by an expanded lip with a wavy periphery ; 
the neck very short with the base recessed into the. 
body of the test; plasma normal, containing Zoo- 
chlorella-cells in symbiotic relationship, also frequently 
oil-like globules; nucleus single, large, granular; one 
or more contractile vesicles usually present; pseudo- 
podia numerous, digitate, simple or branched. 
Length 150-275 -p (Penard). 
Habitat.—Aquatic vegetation and ooze of lakes and 
ponds. : 
Warzs.—Anglesey. 
This species as described by Penard (1902) has a 
well-characterised test and appears to be quite 
distinct from D. amphora Leidy (1874), which was 
afterwards recorded as D. wreeolata var. amphora 
Leidy (1879) and includes forms which belong to 
D. amphoralis Hopkinson (1908); from all these 
D. labwsa is distinguished by the recess around the 
base of the neck of the test, and the wavy collar 
following the undulations of the polygonal aperture. 
In Great Britain itis rare, being only recorded from 
a single locality, and of the following dimensions :— 
length 265 mw; greatest diameter 160 ym; aperture 
65 pw. (Collected by H. HK. Forrest from N.W. Anglesey.) 
6. Difflugia olliformis Lagerheim. 
(Plate LX, figs. 8 and 9.) 
Difflugia olliformis 
LAGERHEIM in Geol. Foren. Stockholm Forh. XXIII (1901), pp. 512- 
513, ff. 1-5. . 
ZACHARIAS in Forschb. Plon, X (1903), pp. 286-287, pl. i, f. 20. 
AVERINTZEFF in Trudui §.-Peterb. Obshch. XXXI, 11 (1906), p. 213. 
ScHOUTEDEN in Ann. Biol. lacustre, I (1906), p. 348. 
Waives in Jrn. Linn. Soc., Zool. XXXII (1913), p. 206, pl. xv, f. 12. 
Difflugia subequalis ? 
‘WAILES in Scott. Natur. 1912, p.63; in Naturalist, 1913, pp. 145-146. 
Test of moderate size, broadly ellipsoidal, truncate ; 
of a yellowish-brown or grey colour, chitinous, sparsely 
