GROMIINA. 101 



The Microgromia; are intermediate in character 

 between the two sub-families ; the pseudopodia arise 

 from a peduncle but are filose in the case of solitary 

 individuals and reticulate when colonies are formed. 



SYNOPSIS OF THE BRITISH FRESHWATER GENERA. 

 Sub-family PSEUDO-GROMIUST^E "Wailes. 



Pseudopodia filose, arising directly from the plasma. 



Test spherical or pyrif orm, flexible, smooth ; aperture 

 flexible. 41. Lecythium. 



Test ovoid, usually rigid, encrusted with foreign 

 particles. 42. Pseudodifflugia. 



Test ovoid, flexible, encrusted with foreign particles 

 and furnished with numerous hair-like cils. 



43. Diaphoropodon. 



Test formed of two valves enclosing a membranous 

 sac. 44. Clypeolina. 



Sub-family ALLOGROMIIN^E Ehumbler. 



Pseudopodia reticulate, arising from a peduncle or 

 raphe. 



Test small, pyrif orm, smooth; often in colonies; 

 nucleus single. 45. Microgromia. 



Test ovoid or pyrif orm, supple, usually smooth, 

 aperture lateral ; one or more nuclei. 



46. Lieberlcuehnia. 



Test oval, moderately rigid, smooth, aperture ter- 

 minal ; one or more nuclei. 47. AUogromia. 



Test cylindrical, usually rigid, often large, encrusted 

 with foreign particles ; one or more nuclei. 



48. Rhynchogromia. 



Sub-family PSEUDO-GROMIIN^I. 

 Genus 41. LECYTHIUM Hertwig and Lesser, 1874. 



Arcella EHRENBEEG (pars) Infusionsth. (1838), p. 124. 

 Gromia SCHLUMBERGER (pars) in Ann. Sci.nat. (3) III (1845), 

 p. 255. 



