110 .BRITISH FRESHWATER RHIZOPODA. 



p. 149, in Bibl. Zool. IV; CALKINS Prot. (1901), p. 56, 



and in Amer. Nat. XXXV (1901), p. 647, f. 1. 

 ? Heterophrys myriapoda ARCHER in Q. J. Micr. Sci. X, n.s. 



(1870), p. 100, t. xvii, f. 4; 

 Heterophrys varians F. E. SCHULZE in Arch. f. mikr. Anat. 



X (1874), p. 386, t. xxvi, ff. 2-5. 

 Heliophrys variabilis GREEFF in Arch. f. mikr. Anat. XI 



(1875), p. 28, t. ii, ff. 20-23; ALLMAN in Jo urn. Linn. 



Soc., Zool. XIII (1877), p. 385, ff. 1, 2. 

 Heliophrys varians G. S. WEST in Journ. Linn. Soc., Zool. 



XXVIII (1901), p. 336. 



Body in the initial (resting) state heliozoon-like, 

 generally with a more or less hyaline margin, and 

 invested with a gelatinous envelope of variable thick- 

 ness, which is fimbriated on the outer edge, and 

 surrounded by numerous short radiating acineta-like 

 processes. The pseudopodia usually rigid, tapering 

 from an expanded base, and formed of hyaline ecto- 

 plasm ; sometimes branched ; in certain (presumably 

 young) states the pseudopodia are straight or whip- 

 like, slender, and mobile, and the animal is destitute 

 of any external covering. During activity the move- 

 ments of the adult are rapid; the body becomes 

 elongated, or roughly triangular, the outer envelope 

 adapts itself to the forms assumed, and the pseudopodia 

 often grouped at the angles become more elongated, 

 extend far beyond the margin of the envelope, and 

 exhibit a tendency to branch, always preserving their 

 rigidity. The body in such individuals is often 

 crowded with bright-green food-particles, with some 

 oil-like globules ; younger ones are freer of coloured 

 matter and more transparent; and a contractile vacuole 

 and one or more nuclei are generally visible. 



Dimensions : Diameter of body (without pseudopodia) 

 40 /A, or over. 



Ponds in Cheshire, 1890. In ditches near Brigg, 

 Lincolnshire (G. 8. West}. In the ooze of ponds and 

 in marshes, Ireland (W. Archer) . 



Considerable ambiguity has always hung around 



