78 BRITISH FRESHWATER RHIZOPODA. 



1. Difflugiella apiculata Cash. 



(Plate XX, figs. 17 and 18.) 



Difflugiella apiculata CASH in Jrn. Linn. Soc,, Zool. XXIX 

 (1904), p. 225, t. xxvi, f. 7; AVERINTZEV in Trudui 

 S.-Peterb. Obshch. XXXVI (1906), 2, p. 259; SCHOU- 

 TEDEN in Ann. Biol. Lacustre, I, 3 (1906), p. 359, f. 60. 



Characters those of the genus. The test apparently 

 little more than a chitinous film, flexible in the lower 

 part. The plasma, as a rule, filled with fine granules 

 and chlorophyllous material, with two or three 

 vacuoles, and an inconspicuous nucleus. The cavity 

 of the test more than three-fourths occupied. The 

 abnormal character of the pseudopodia, when the 

 organism is active, at once arrests attention. 



Dimensions : Length about 40 p. ; breadth 28 /u,. 



Amongst floating Confer VSR and other vegetation in 

 a broad and shallow stream crossed by the Barking 

 and Purfleet road, about a mile from the town of 

 Barking, May, 1901. 



The permanence of the pseudopodal character seems 

 to admit of no doubt, as a number of individuals, care- 

 fully examined, exhibited it clearly. The apiculate 

 pseudopodia were generally very mobile, whilst the 

 more elongated lateral ones were rigid, and showed 

 little disposition to alter. 



Genus 23. CRYPTODIFFLUGIA Penard, 1890. 



Cryptodifflugia PENARD in Mem. Soc. Geneve, XXXI (1890), 

 2, p. 168 (generic name) ; Faune Rhiz. Leman (1902), 

 p. 425 (the genus described). 



Minute, Di/^w/ta-like organisms, with a chitinous 

 (generally yellowish or brownish) compressed and 

 smooth test, which has in most cases some investment 

 of foreign particles ; the granular plasma not filling 

 the entire cavity, and the pseudopodia which are 

 long and acutely pointed more numerous and less 

 ramifying than in Phryganella. 



