VAMPYRELLA YOEAX. 103 



indicated by any definite marginal line. Progression 

 is mostly lateral, the broad side in advance emitting a 

 mass of radiating pseudopodal filaments, some long and 

 fine, others short and faintly capitate. Xo nucleus or 

 contractile vacuole is visible. Reproduction is effected 

 by encistment and the formation of swarm-spores. 



Dimensions variable ; average length, exclusive of 

 pseudopodia, 40-70 fi ; breadth 20-30 p.. 



In ponds, amongst Confervae and floating Hypna; 

 Cheshire. 



The habits of this species are not less singular than 

 those of the preceding, from which, however, it differs 

 very materially in form. The plasma-body is remark- 

 ably fluid. Two individuals, coming together, fuse 

 like drops of water, and, this having taken place, the 

 compound organism pursues a career in all respects 

 like that of the previously separate individuals, the 

 only apparent difference being its increased size. 



This condition of V. vorax was found by Klein to 

 follow encistment. The contents of the cist break up 

 into " swarm spores," which attain their freedom, 

 conjugate, and later form either double or multiple 

 individuals (plasmodia). An example is figured 

 (Plate XI, fig. 4) of two individuals, each containing a 

 diatom incepted as food, having united in the manner 

 described. As many as four are said to have been 

 observed to fuse in this manner. 



The movements of the animal are habitually lateral. 

 A considerable number of tentacle-like filaments are 

 thrown out in the direction of progression. 



3. Vampyrella flabellata Cash. 

 (Plate XI, figs. 7-12.) 



Vampyrella flabellata CASH in Journ. Linn. Soc., Zool. XXIX 

 (1904), p. 224, t. xxvi, ff. 5, 6. 



In structure resembling the preceding species, and 

 about the same in size, but differing in habit; most 



