DRAPARNALDIA. 123 



5. DRAPARNALDIA TENUIS Ag. 

 Plate XL Fig. 2. 



Char. Filaments slender, ciliated, sparingly branched. 

 Branches usually simple and solitary, but sometimes sub- 

 fastigiate. Cells of the stems twice or thrice as long as 

 broad, those of the branches rather longer than broad. 



Hob. Streams near Cheshunt : A. H. H. Reservoir, Ar- 

 drossan : Major Martin. Between Pembury and Tun- 

 bridge; Hawkhurst and Gondhurst, Kent: Mr. Jenner. 



This is a much smaller species than any of the preceding, 

 is more tenacious, and an inhabitant of streams and rivulets, 

 the current of which is strong. Filaments very slender, four 

 to six inches long, irregularly or alternately branched, more 

 or less furnished with scattered or subfasciculate ramuli, 

 whose tops are either acute or drawn out into long setaceous 

 colourless points. Joints of the main filaments and ramuli 

 coloured or transversely banded. " At first the filaments are 

 enclosed in the manner of a Chcetophora in a common some- 

 what definite gelatine ; afterwards, on its bursting, they issue 

 from it like a Conferva, but are at all times very gelatinous." 

 Harvey, Manual of Brit. Algoe, p. 122. 



6. DRAPARNALDIA ELONGATA Hass. 

 Plate X. Fig. 3. 



Char. Filaments very slender, ciliated. Cells fasciated, usually 

 three times as long as broad. 



Hassall, in Annals of Nat. Hist, for August, 1842 ; also 

 in loc. cit. vol. xi. p. 4. 



Hab. Cheshunt : A. H. H. Parkind : Major Martin. 



The filaments in this species are finer than those of D. 

 tennis, and the cells longer. I have no doubt of its dis- 

 tinctness. It is a rare species, and I have only twice met 

 with it, once growing in a horse trough near Cheshunt. 



