ACTINOPHRYS SDBALPiNA. 25 



Penard's species, however, flourishes in quiet pools 

 and lakes ; its diameter is 60 /a to 80 /x,. 



Further records and observations of A. subalpina in 

 this country are to be desired. 



Sub-order II. OHLAMYDOPHORA Archer. 



Body invested with a mucilaginous envelope con- 

 taining no silicious or other scales. 



Only one freshwater genus is included in this 

 sub-order. 



Genus 3. ASTRODISCULUS GreefE. 

 Astrodisculus Gbeefp Aroh..Tnikr. Anafc. V, 1869, p. 496. 



Envelope mucilaginous, transparent, free from inclu- 

 sions, occasionally absent. 



Body spherical; ectoplasm merging gradually into 

 the endoplasm ; pseudopodia tenuous and not usually 

 granuliferous. 



A. radians is the only species of this genus that 

 has been recorded from the British Isles up to the 

 present. 



Three other species are described by Penard 

 namely : 



A. araneiformis Schewiakoff. The mucilaginous envelope 

 may or may not be present; the pseudopodia are long (30 jx 

 to 40 /i) with bead-like expansions along their length; the 

 nucleus is placed centrally ; the contractile vesicle prominent. 

 Diameter 15^. 



A. laciniatus Pen. The envelope thick with the outer 

 surface fimbriated; nucleus placed eccentrically ; pseudopodia 

 very numerous, tenuous and finely granuliferous. Diameter 

 over the envelope 42 ix. 



A. zonatus Pen. Envelope double, the outer portion the 

 thicker; nucleus placed centrally; pseudopodia tenuous, with- 

 out granulations. Diameter 40 /z to 45 fi including the 

 envelope. 



