ASTKODISCULIS K'.U'iAXs. "27 



adhering to it ; ectoplasm merging gradually into the 



O 1 v 



endoplasm and more or less loaded with granules of a 

 green, yellow or brown colour ; pseudopodia attenuate, 

 straight, not granuliferous, of moderate length ; nucleus 

 not large, placed eccentrically ; a single contractile 

 vesicle usually present. 



Diameter of body 13 p to 17 /x (Penard) ; 25 ^ 

 (W'-'t). Diameter of mucilaginous investment about 

 twice that of the body. 



Habitat. Pools and ditches. 



Distribution. ENGLAND. Brigg, Lincolnshire 



OO 7 



(West). 



SCOTLAND. Inverary (L'rotrn). 



Some of the pseudopodial axes frequently do not 

 project beyond the mucilaginous zone, and it is pro- 

 bably to these that Greeff refers when he speaks of 

 spicules being imbedded in the outer envelope. 



Heliap/n-i/x variant* (Schulze) as described by West 

 (1901) is undoubtedly an Astrodisculus, and differs 



from A. railiiiii* onlv in its slightlv larger size and the 



*' " 



branching of some of the pseudopodia. 



Hetrr<>i>!i ///* rurians Schulze and Hcln^ilirij^ atrlnlii/i'* 

 Greeff appear to lie X/idciiria and not identical with 

 A. radians. 



Sub-order III. CHALAROTHOKACA Hertxvi.g & 



Lesser. 



Heliozoa having an external envelope composed of 

 solid elements with or without a matrix of plasma. 



SYNOPSIS OF THE FI;KSH\YATI:I; GEXF.KA. 



(a) Envelope consisting of a thick layer of plasma contain- 

 ing 



Chitiuous spicules. (4) Heterophrys. 



Silicions spicnle-. (5) Raphidiophrys. 



Spicules of special forms. 



