26 BRITISH FRESHWATER RHIZOPODA. 
Test discoid, formed of a yellowish-brown, homo- 
geneous, flexible membrane, the crown convex, the 
periphery prolonged into a diaphanous membrane 
capable of completely closing in the base of the test ; 
the crown usually sparsely covered with small adherent 
foreign particles; plasma partly filling the test, the - 
ectosare colourless and limpid, the endosare containing 
numerous minute yellow-brown granules; nuclei two 
in number, usually placed close together; contractile 
vacuoles variable in number; pseudopodia few, short, 
lobular or broadly digitate. 
Diameter 80-100 w or more; young and immature 
individuals may be as small as 20 u in diameter. 
Habitat.—Mosses. 
Encianp.—Westmorland (Brown); N. and W. York- 
shire (Brown); Bedfordshire; Shropshire; Isle of 
Wight; Cornwall; Isles of Scilly. 
Wares.—Anglesey. 
Trwtanp.—Clare Island and Inishturk, Mayo; Inish- 
bofin, Galway. 
The synonymy of this species seems inextricably 
mixed; Cash, following Archer, refers Ainphizonella 
flava Greeff to Pseudochlamys patella Clap. & Lachm. 
(Vol. I, p. 129); Penard, whose name for this species 
is now generally adopted, points out (‘Archiv f. 
Protist.,’ Vol. XVII, p. 260) that the earlier writers 
in many cases gave insufficient descriptions and often 
no drawings of the species described ; also that Corycia 
[Microcorycia] flaca when young or. immature closely 
resembles the adult Psendochlamys patella and both 
species possess tests capable of taking a variety of 
shapes. The plasma however is very distinct in the 
two species. M. flava usually lives only in the drier 
mosses, such as grow on trees, walls, and rocks, and 
also in those growing on the ground. From such 
situations the tests are hable to be carried into ponds 
where Psendochlamys patella is usually found. 
