92 BEIT1SH FRESHWATER RH1ZOPODA. 



normally circular, though sometimes, from being closely 

 crowded, sub-hexagonal, the interspaces forming ele- 

 vated ridges which make the surface rugose. The test 

 is very transparent. The animal is graceful in its 

 movements, but very timid. 



9. Hyalosphenia nobilis sp. nov. 

 (Plate XXV, figs, 1-3.) 



Test of translucent chitinous membrane, flask-shaped, 

 the body in side view forming a perfect ellipse, with a 

 long cylindrical neck truncated at the mouth, which 

 is circular in outline and faintly undulated on the 

 margin. In dorsal or transverse view the test is uni- 

 formly circular ; its whole surface pitted with irregu- 

 larly-formed depressions. The protoplasm generally 

 filled with chlorophyllous pellets and oil-like globules ; 

 the nucleus conspicuous, situated in the posterior 

 region. Pseudopodia four to six, simple, usually short 

 and colourless. 



Dimensions : Average length 200 ju, ; greatest width 

 90 p. ; diameter at the mouth 30 p. 



Amongst aquatic mosses and other vegetation on 

 Knutsford Moor, Cheshire; August, 1891. 



This large and particularly elegant rhizopod occurred 

 in considerable plenty amongst the rootlets of Aula- 

 comnium palustre. It has a test of glassy transparency, 

 perfectly colourless, with a rugose surface caused by 

 the pits, and devoid of incrustation. The form of the 

 test, so different from that of other HijctlosplienidB in 

 exhibiting not the least indication of compression, first 

 led us to class it with the Difflugise. The homogeneous 

 test, however, notwithstanding the circular transverse 

 section it presents, indicates a closer affinity with 

 Hyalosphenia, and to that genus we have accordingly 

 removed it. 



