VAMPYRELLA LATERITIA. 97 



elongated and filamentous pseudopodia, and intermixed 

 with them a variable number of shorter and stouter 

 capitate processes which elongate and contract inces- 

 santly. Wave-like or lobate expansions of clear 

 ectoplasm, and sometimes also digitate processes, are 

 frequently emitted from the periphery. No nucleus 

 of the normal type has been detected in this species, 

 but Zopf demonstrated the presence of scattered grains 

 of nuclear substance. The animal is stated by most 

 observers to be destitute of a contractile vacuole, but 

 in some states (probably young) one, if not more, is 

 undoubtedly present, though obscured more or less by 

 the brick-red contents of the plasma- body. The 

 chlorophyl of filamentous algae seems to form the sole 

 food of V. lateritia, but the animal does not confine 

 itself to any particular species. It glides through 

 the water with a motion similar to, but more rapid 

 than, that of Actinophri/s, and on coming in contact 

 with an alga-filament will often travel along it and 

 sometimes break it at the joints, or pierce the indi- 

 vidual cell, in order to extract the chlorophyl. 



Dimensions variable, averaging 30-40 //, in diameter. 



In shallow bog-pools, amongst wet Sphagnum, and 

 occasionally in ponds and ditches amongst Confervse. 

 Not infrequent in Cheshire, associated with Acantho- 

 cistis, etc. ; and in Epping Forest. Near Brigg, 

 Lincolnshire; Harris, Outer Hebrides (G. S. West}. 



The habits of this species make it one of the most 

 interesting of the tribe. The Khizopoda, as a rule, feed 

 on such things as fall in their way. They are gleaners 

 merely. Vampyrella lateritia, on the contrary, seems 

 to hunt for its food, and has, in a very humble degree, 

 a power of selection. Once found, a filament of Spiro- 

 gyra, or other allied alga, is taken possession of by 

 the Vampyrella, and not given up until the animal's 

 needs are satisfied, when it usually passes into an 

 inert or resting state in which it will remain for an 

 indefinite period. Its method of attacking a filament 



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