BRITISH FRESHWATER HELIOZOA. 15 



BRITISH FRESHWATER HELIOZOA. 



The arrangement of the sub-orders and genera is 

 as follows : 



Sub-order I. APHROTHOKACA. 

 Genera: (1) Actinosphaerium, ('2) Actinophrys. 



Sub-order II. CHLAMYDOPHORA. 

 Genus : (3) Astrodisculus. 



Sub-order III. CHALAROTHORACA. 



Genera: (4) Heterophrys, (5) Eaphidiophrys, (6) 

 Pompholyxophrys, (7) Lithocotta, (8) Elasorhanis, (9) 

 Acanthocystis. 



Sub-order IV. DESMOTHORACA. 



Genera: (10) Clathrulina, (11) Hedriocystis. 



Sub-order I. APHROTHORACA R. Hertwig. 



Heliozoa without envelope or investment to the 

 body except during encystment. 



SYNOPSIS OF THE BRITISH G-ENERA. 



Multi-nuclear . . . . (1) Actinosphserium. 



Nucleus single and placed centrally (2) Actinophrys. 



Gen as 1. ACTINOSPHJERIUM Stein. 



Actinosphserium STEIN Abh. Bohmisch. Ges. (ser. 5) X, 

 Berichte, 1857, p. 41. 



Ectoplasm consisting almost entirely of large 

 vacuoles in one or more layers ; endoplasm contain- 

 ing numerous small vacuoles ; nuclei more or less 

 numerous. 



Only two species are included in this genus. 



