BRITISH I'RESUWATER RHIZOPODA. 223 



ones were formed. The pseudopodal filaments were extremely 

 fine, extended into the surrounding medium to distances often 

 five or six times the diameter of the body, and anastomosed 

 spariogly. The protoplasm of the body-mass and pseudopodia 

 was colourless, or pale and faintly granular. Some of the finer 

 filaments — usually simple ones — were exceedingly mobile. 



The organism has since been met with more abundantly 

 elsewhere. 



Grenus Penardia, gen. nov. 

 Body when at rest roundish or ovoid ; at other times expanded 

 and, during progression, exceedingly mobile ; the endoplasm a 

 deep chlorophyllous green, with a marginal band of ectoplasm ; 

 the pseudopodal filaments slender, branching and anastomosing, 

 ultimately forming a widely-spreading network. The ectoplasm 

 greyish, granular; the finer filaments faintly granular, colourless. 

 Nucleus inconspicuous or absent ; contractile vesicles (one or 

 more) usually near the periphery of the endoplasm. 



Penardia mutabilis, sp. nov. (PI. 26. figs. 1, 2.) 



Body when at rest roughly ovoid, with almost inert branching 

 and anastomosing pseudopodia projected from the surface ; the 

 central mass opaque or semiopaque, without definite structure. 

 When en marclie the animal becomes exceedingly mobile, 

 expanding, elongating,.and contracting incessantly, and throwing 

 out a widely-extending network of pseudopodia which are used 

 for the capture of prey. 



In this mobile state the body is flattened out and becomes 

 transparent, exhibiting a central mass (having a well-defined 

 general outline) of a bright green colour, consisting apparently 

 of a great number of minute oval bodies, closely compacted, but, 

 so far as is known, without a nucleus. The hyaline ectoplasm 

 is of varying width and is but slightly granular, changing with 

 the pseudopodal movements. 



Dimensions: length of body, irrespective of pseudopodia, 130 

 to 200 fi, or more ; breadth variable. Diameter when at rest 

 averaging 80 jjl. 



Amongst Sphagnum in a small swamp in Epping Porest, on 

 the right of the road leading to Copped Hall Lodge, from the 

 Epping highway, associated with colonies of JMLicrogromia socialis 

 and with PompJiolyxophrys punicea, Arch., &c., 1901. 



The animal did not occur abundantly in the locality mentioned, 



