104 BRITISH FRESHWATER RHIZOPODA. 
frequently appearing as an ovoid or double-convex 
elongated body, narrowed at the extremities, each 
extremity being furnished with a bundle of short, 
capitate, pseudopodal filaments, with other simple ones 
intermixed. One or more filamentous pseudopodia 
are usually to be seen projecting from the body-surface, 
but these are inconstant, appearing and disappearing 
at various points. Not infrequently the entire body 
becomes remarkably elongated, when it appears as 
though a long, tapering pseudopodium had been thrust 
out posteriorly (Pl. XI, figs. 8, 11) whilst the anterior 
plasma expands and takes a fan-shaped outline, clothed 
with pseudopodal filaments of varying length, the 
shorter ones mostly capitate. The posterior prolonga- 
tion is induced by the adhesion of the plasma-body, 
at a point on the convex surface, to some foreign 
object (or to the glass slip over which it is moving) 
whilst the forward movement is continued, the body 
posteriorly thus becoming more and more attenuated, 
smooth throughout, and terminating in a sharp point. 
The food of the animal consists of minute diatoms. 
Like the preceding species it is destitute of contractile 
vacuole, and apparently also (so far as has been 
observed) of nucleus. Its life-history is unknown, 
though it may be presumed to be analogous to that of 
V. vorav, with which it is most nearly allied. 
Dimensions : Length of the ovoid body 60-70 p; 
average breadth 20-30 ». When elongated, measuring 
from the convex face to the posterior extremity, 110 p, 
or more. 
In water from a sluggish stream near Barking, 
Essex, amongst Conferve, etc., May, 1901. 
V. flabellata may be distinguished from V. vorax by 
its paler colour, and also by its peculiar movements. 
It is very active, and its pseudopodal changes are 
unceasing. The examples which furnished the above 
description (and which were kept under observation 
for a considerable time) had little or none of the red 
