PLAGIOPYXIS CALLIDA. AZ 
Walt.es in Jrn. Linn. Soc., Zool. XXXII (1912), pp. 128, 181, 159; 
(1913), p. 212. 
BEMONDEON i in Ward & Whittle’s Fresh-water Biology (1918), p. 226, 
0 
Test of medium size; grey, yellowish or brown in 
colour; ovoid with ventral side flattened or concave 
and pierced by a linear, lunate aperture, the inner lp 
of which is continued nearly parallel to the side of the 
text for two-thirds of the: distance to the crown; 
plasma limpid, grey in colour, containing numerous 
small, pale, spherical granules ‘and occasionally’ food- 
particles of vegetable origin; nucleus large, spherical, 
with numerous minute nucleoles; a single vacuole 
occasionally present; pseudopodia numerous, radiating, 
short, broad, pomted or palmate, very rar ely observed. 
Diameter 55-135 p, but usually 90-110 p. 
Habitat.—Mosses. 
Exauanp.—Cumberland, Westmorland, and Lanca- 
shire (Brown); N. Yorkshire; Shropshire; Bucking- 
hamshire ; Cornwall; Isles of Scilly. 
ScorLanp.—Hlginshire (Brow). 
Tretanp.—Clare Island and Inishturk, Mayo ; Inish- 
bofin, Galway. 
This is a widely distributed and often numerously 
represented species; the test 1s dark and opaque. 
This, together with its narrowness, often renders the 
aperture very difficult to locate. The pseudopodia 
are so rarely observed that only once has their appear- 
ance been recorded, a result achieved by Penard after 
lengthy observations. The geographical range is 
extensive, records extending to both the Northern 
and Southern Hemispheres. 
Genus 18c. CUCURBITELLA Penard, 1912. 
Difflugia (pars) Lerpy Fresh. Rhiz. N. Amer. (1879), p. 114. 
Cucurbitella Penarp Faune Rhiz. Léman (1902), pp. 315. 311. 
Test ovoid, not compressed, formed of variously- 
shaped silicious grains; aperture terminal, circular, 
