FRESHWATER RHIZOPODS AND HELIOZOA. 333 
Order VAMPYRELLIDA. 
Gen. VamMPYRELLA, Cienkowshi. 
54. VAMPYRELLA LATERITIA, Letdy, Freshw. Rhiz. N. Amer. 
1879, p. 253, t. xlv. ff. 10-16.—Ameeba lateritia, Fresenius, 
1856-8. Vampyrella Spirogyre, Cienk. in Archiv fiir mikr. 
Anat. i. 1865, p. 218, tt. xi—xil. ff. 44-56 ; Hertwig § Lesser, in 
Arch fiir mikr. Anat. 1874, x. Suppl. p. 61, t. 1. f. 2. 
Near Brigg, Lincolnshire. Diameter of animal without 
pseudopodia 23-32; diameter inclusive of long pseudopodia 
67-77 p. (Pl. 29. figs. 29-31.) 
The Heliozoén-like form was abundant in a ditch amongst 
Lemna minor. The body of the animal was rarely globular, 
generally being ellipsoidal or even oblong. Outside the bright 
red, pigmented mass was a zone of clear protoplasm from which 
radiated a number of delicate pseudopodia of considerable length. 
Between the bases of these delicate pseudopodia the clear zone 
also gave origin to a number of much shorter, thicker pseudo- 
podia, which, although only capable of comparatively slow move- 
ments, were extended or retracted more quickly than the elongate, 
delicate, protoplasmic filaments. 
I was sufficiently fortunate to observe several of these animals 
feeding on the cell-contents of a species of Mougeotia. They 
-have frequently been described as feeding on Spirogyra, but I 
know of no recorded instance of a species of this genus attacking 
a filament of Mougeotia. The animal attached itself firmly to 
the lateral margin of one of the cells of the filament, and in a 
very short time the long, delicate pseudopodia were retracted. 
At the same time the clear, outer, protoplasmic zone was con- 
tinually putting forth and retracting shorter and stouter pseudo- 
podia. That portion of the animal which originally attached 
itself to the cell very soon had perforated it, a portion of the 
animal protoplasm passing into the cell and causing a violent, 
dancing movement of the granules of the vegetable protoplasm. 
Whilst this was happening the chromatophore of the Mougeotia- 
cell was observed to be disintegrating at a point immediately 
opposite the place of attachment of the animal. I watched this 
destruction go on for about two hours; it was accompanied 
by much violent movement on the part of the small granules of 
the protoplasm, but during that time only a portion of the 
