AMCEBA PILOSA. 63 



one or more. The posterior extremity is produced 

 into a delicately-fringed extension of faintly granular 

 protoplasm, in which are usually to be seen one or two 

 small vacuoles. Its external outline is irregular, with 

 a tendency to become lobate. The entire body of the 

 animal, including the posterior expansion, is covered 

 with delicate spicules, radiating outwards, of equal 

 length, and closely resembling those which invest the 

 membranous test of Cochliopodium vestitum. This 

 latter character at once distinguishes A.pilosa from all 

 other known forms of Amoeba. Locomotion is effected 

 by lobular expansions of the ectoplasm, anterior or 

 lateral. As in A. proteas and A. villosa the pseudo- 

 podia may originate at any point of the body-surface. 

 They have never been observed to become digitate. 



Dimensions: Length about 180 /A; average breadth 

 50 p.. 



In ponds at Chelford, Cheshire, amongst floating 

 vegetation ; associated with Mastig amoeba aspera 

 Schulze, Ciliophrys infusionum Cienk., etc. ; June, 

 1903. In similar situations at Fearnhead, Lancashire. 



It is difficult to explain the origin and purpose of 

 the delicate processes which so completely invest the 

 body of this animal. Careful observation showed that 

 upon the formation of a pseudopodal lobe, or broad 

 eruptive expansion of the ectosarc, the spicules in- 

 stantly flowed over it from the surrounding surface ; 

 the continuity of the investment was thus ensured 

 during all the animal's movements. 



The Fearnhead examples of A. pilosa presented 

 some differences from the typical Chelford form. 

 They were probably older individuals. The investiture 

 was the same, but it was observed that the individual 

 spicules were stouter, and many of them were darker 

 in colour, assuming often a yellowish-brown hue, 

 whilst the endoplasm of the animal was denser. The 

 posterior expansion was entirely wanting, and the 

 animal was much less active. 



