224 THE ALGA-FLORA OF CAMBRIDGESHIRE. 
211. T. reticunaris (Reinsch) Hansg. 5. Chippenham Fen. 
212. Protococcus virmis Ag. 38. On stones, Orwell. 
Class MYXOPHYCEA. 
Order Hormoconez. 
Subord. Hetrrocyste. 
Fam. Rivunariaces. 
*213. Canorurr Frusca (Kiitz.) Born. et Flah. in Ann. Sci. Nat. 
Te série, Bot. iii. 364 (1886). 3. Sheep’s Green, hpi a: 
Wimpole Park. In both instances the plants occurred either a 
solitary filaments or slightly gregarious, attached to Folch 
sessilis, Crass. fil. 7-18 pw; crass. trich. 5-8-5 p. The heterocysts 
were basal, singe or in pairs, and difficult of observation, owing to 
a thick, opaque mass of extraneous material usually found aggluti- 
nated round the bases of the filaments at their point of attachment. 
This is the first instance of this alga having been fo und in Britain, 
and its occurrence as an epiphyte on Vaucheria is rathe 
as it is usually found on such alge as Batrachospermum, Chato- 
phora, &c., Which possess a more gelatinous thallus 
*214. C. eprpnytica West & G. S. West, Welw. Afric. Alg.’ 
Journ. Bot. 1897, 240. 8. Guyhirne, on Vaucheria dichotoma. 
Crass. fil. 8 »; crass. trich. 4 A much smaller ps st than the 
Sac aa and only yond observed from West Africa. 
5. Rivunari pura Roth. 5. Wicken Fen: very abindlll in 
pools and peaty Siehal: oe 1898. Forming olive- or dark green 
hemispherical masses oe size, attached to Myriophyliam 
spicatum and Chara hispi dl Grass. trich. 6°5-10 p (usque ad 
11:5) »; heterocysts roa sae lat. 5°5-10 e long. _ 5 ps 
*216. R. mmnurvta (Kiitz.) Born. et Flah. 5. Chippenham Fen. 
This species was attached to the submerged portions of Fhvopates 
communis, forming little pulvinate masses of a bright blue-green 
colour. Crass. vagin. 16-25 pw; crass. trich. 9°5-13°5 p; hetero- 
cysts subglobose or hemispherical, diam. 9-11 p. Although this 
interesting species has not been previously recorded for England, it 
as a wide ROI IE on the continent, and may probably have 
rata overlooked in this 
217. Gia@orricara sie (Ag.) Thur. 8. a i Ree River, 
between March and Guyhirne: very scarce, July, 1898. 
Fam. SrrosipHoniacEz 
218. Sriconema ocetnarum (Dillw.) Thur. 5. Chippenham Fen, 
among Utricularia vulgaris, 
— ScyToNEMACER. 
9. Tonyporrix a (Desv.) Wartm. Syn. T. coactilis 
Kitz.; T. asapresite (Kitz,) Rabenh. 5. Wicken Fen, on the 
leaves ‘of Nymphea alba. 7. In large quantity in a pond about two 
miles §. Maxéh 8. Twenty-foot River, betwen March and 
Guyhirne. 
