HETEROPHKYS KADIATA. 33 



observed ; nucleus single, placed eccentrically ; no 

 central granule observed ; pseudopodia numerous, 

 long, delicate, granuliferous ; no pulsating vesicle 

 observed. 



Diameter of body 21 ^ ; diameter of outer envelope 

 53 fji ; length of pseudopodia 43 ^. 



Habitat. On vegetation (M't/riophyllum) in ponds. 



Distribution.- -^NGLAND.- - Epping Forest, Essex 

 (Went). 



None of the observed individuals contained any 

 green algal cells. 



The pseudopodia had numerous relatively large 

 granules scattered at intervals along their length. 



Genus 5. RAPHIDIOPHRYS Archer. 



Raphidiophrys ARCHER Qrt. Jru. Micr. Sci. (N.S.) VII, 1867, 

 p. 179. 



Body enclosed in a mucilaginous envelope contain- 

 ing spicules, spindle-, awl-, or disc-shaped, which 

 normally extend outwards along the pseudopodia; 

 nucleus and.endoplasm placed eccentrically. 



The identification of the species in this genus 

 largely depends on the shapes of the investing 

 spicules; this may necessitate the isolation of the 

 individual and its examination either in a diy state 

 or after treatment with sulphuric acid ; in either case 

 a high magnification is desirable. 



The following is a short description of the species 

 belonging to this genus which have not up till now 

 been recorded from the British Isles : 



R. socialis Leidy. Usually in large colonies in which the 

 individuals, sometimes as many as one hundred, are loosely 

 associated ; spicules numerous, straight, extremely tenuous ; 

 several contractile vesicles may be present; the nucleus 

 stated to be placed centrally, but as Leidy gave no drawing 

 and no subsequent record has been published this statement 

 requires corroboration. Individuals 24 ju. to 36 fj. diameter of 

 body. 



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