58 BRITISH FRESHWATER HEMOZOA. 



Habitat. — Sediment of moorland pools and ditclies. 



Distribution. — England. — Derbyshire ( Wailes) . 



The pseudopodia are so attenuated that they are 

 often difficult to detect ; when the skeleton is examined 

 in a dry state the spines are seen to haye enlarged 

 bases shaped like pin-heads. 



Sub-order IV. DESMOTHORACA Hertwig & 

 Lesser.. 



Heliozoa with an envelope or capsule homogeneous, 

 continuous and perforated, often provided with a 

 pedicel or stalk. 



Synoi\sis of Britijsh Freshwater Genera. 



Capsule stalked, openings in it comparatively large and 



numerous. (10) Clathrulina. 



Capsule stalked, openings in it minute and not so numerous. 



(11) Hedriocystis. 



Genus 10. CLATHRULINA Cienkowsky. 



Clathrulina Cienkowsky Arch. mikr. Anat. Ill, 1867, p. 311. 

 Podosphxra Aechek Qrt. Jrn. Micr. Sci. (n.s.) VIII, 1868, 

 p. 67. 



Envelope spherical, homogeneous, pedunculate, pro- 

 vided with numerous openings usually regularly 

 placed ; plasma centrally placed, not filling the test ; 

 nucleus, except during division, single, placed centrally; 

 pseudopodia numerous, tenuous, granuliferOus, straight 

 or forked. 



The species C. stuhlmanni has an envelope pierced with 

 very small openings and is provided with a very long stalk; 

 it has up to the present been recorded from Africa only. 



Synopsis of British Species. 



Openings in envelope large. C. elegans. 



Openings in envelope smuU. C. cienl-uir.skii. 



