64 - BRITISH FRESHWATEE HELIOZOA. 



1. Hedriocystis reticulata Penard. 



(Plate LXXIV, figs. 1-4.) 



Hedriocystis reticulata 

 Penard Heliozoaires, 1904, p. 284, figs. 

 Brown Ann. Scot. Nat. Hist. 1911, p. 231. 



Capsule stalked, transparent, thin, colourless or of 

 a pale yellow, spherical with numerous facets more or 

 less regularly polygonal and having raised borders ; 

 stalk of moderate length, straight, solid; body spherical, 

 not filling the capsule ; plasma bluish in colour, con- 

 taining refringent granules and food particles ; nucleus 

 single placed sub-centrally ; one contractile vesicle 

 normally present and usually active ; pseudopodia 

 without axes, each issuing from a pore in the centre 

 of a facet ; habit solitary. 



Diameter of capsule about 25 jjl ; stalk about 70 /x 

 in length and 1 /i, to 1'5/x in diameter. Diameter of 

 body about 12 ju. 



Habitat. — Marshy pools. Rare. 



Distribution. — Scotland. — Craigcaffie {Broivv). 



Both capsule and stalk are of a chitinous material, 

 and the former is so transparent and colourless that 

 only the ridges bounding its polygonal faces are 

 apparent ; the pores are indicated only by the pseudo- 

 podia that issue from them except when treated with 

 acid when small bubbles of gas serve to localise them. 



Division within the capsule has been observed, but 

 the method of escape from it has not been recorded. 



2. Hedriocystis spinifera Brown. 



(Plate LXXIII, figs. 2-4.) 



Hedriocystis spinifera 



Beown Jrn. R. Micr. Soo. 1918, p. 172, S. 5-7 on pi. 



Capsule minute, similar to that of the preceding 

 species, but furnished with spines arising at many o'f 

 the junctions of the alveolar ridges ; body spherical, 



