64. BRITISH FRESHWATER RHIZOPODA. 
containing several small nucleoles, placed posteriorly ; 
pseudopodia few in number, digitate, simple. 
Length 60-70 yw; breadth 45-55 mw; aperture 20- 
25 w; nucleus about 15 pw in diameter. 
Habitat.—Sphagnum. 
Eneruanp.—N. Yorkshire; Bedfordshire; Shropshire; 
Buckinghamshire; Isle of Wight; Somersetshire ; 
Cornwall. 
Wates.—N. Wales. 
ScortanD.—Outer Hebrides. 
Iretanp.—Mayo and the islands off Clew Bay; 
Tnishbofin, Galway. 
The only other species of Heleopera resembling this 
is H. sphagni var. levis Wailes (‘ Journ. Linn. Soc.,’ 
Zool., vol. xxxii (1912), p. 143), which however 
usually exceeds it in size, has a smoother fundus, and 
is of a characteristic yellow colour; the test also has a 
peculiar reticulated structure (v. Leidy, 1879, Pl. xxvi). 
H. sordida is also peculiar among the species of the 
genus in having vegetable débris attached to the 
fundus ; this is easily confirmed by immersing the test 
in a chlor-zinc-iodine solution which stains vegetable 
tissue a dark red; also when the tests are mounted in 
canada balsam the vegetable particles usually appear 
black. 
It is a widely distributed species and occurs on the 
Continent of Europe, in North and South America, 
Australasia, and the Seychelles. 
Genus 27a. AVERINTZIA®* Schouteden, 1906. 
Heleopora. (pars) Prnarp Faune Rhiz. Léman (1902), 
pp. 390-393. 
Awerinzewia Scuourepen in Ann. Biol. lacustre, I, 1 (1906), 
p. 397. 
* This alteration in spelling from the German form of Awerinzewia seems 
to be the nearest approximation to the transliteration into English, with 
generic form of termination, of the Russian characters in the name of the 
distinguished biologist in whose honour this genus was founded, and is in 
accordance with Latin orthography, which the German form is not. 
