NOTES ON FRESHWATER ALGE 291 
cells, the relative size, and the habit of the plant admit of no 
other conclusion. We find it frequently in bogs, and the fact 
that it is invariably associated with Desmids that were perfectly 
familiar to Brébisson tends to we som view “pe = — 
we have had under observation for 
paige i sang the same as the slant ated. ‘a ppg se 
as EF, | 
8. vi Bae “ape sp.n. [Syn. X. Smithit Arch. var. 
variabile Nordst. 1887; in Kongl. Sv. Vet.-Akad. Handl. Bd. 22 
no. 8, , p. 44, t. iv. f. ” 97-39 West and G. S. West in Journ 
Roy. Micr. Soc. 1896, p. 156, t. iv. f. 10; “Deal Journ. 
Linn. Soe. Bot. vol. xxvii. 1899, p. 386, t. 8, f. 2 
Distrib. England; Wales; Ireland ; British, Guiana ; New 
Zealand; Australia 
During the last few years we have obtained this plant from 
many parts of England, especially from some of the Sphagnum- 
bogs. It often occurs in digious numbers, and retains its 
ciated with X. Smithii, although we have had the latter in abundance 
° 
its great variability, yet no intermediate forms are met with which 
in Se ay tend to connect it with X. Smithii (cfr. G. S. West, lc. 
p. 386). 
9. XanrHipium = heegrg art Wolle, 1882; slp U. 8. p 95, 
t. xxii. figs. 8, 9; West & G. S. West, ‘N. Amer. Desm.,’ ‘and, 
Linn. Soc. Bot. ser. . vol. vy. p. 258, 6. xv. f. rv [Syn. Arthro- 
desmus incrassatus jLagerh. in Otvers. af K. ‘Sy. Vet. iad, Forh. 
1885, no. 7, p. 242, t. i. £. 18. 
ar. ype Sasha ted (Roy & Biss.) rg [Syn. X. quadricornu- 
tum Roy & Biss. in Ann. Scot. Nat. Hist. 1898, p. 245; 1694, t. iv 
f. 5.] The species described by Messrs. Roy and Bissett as x. quadri i- 
cornutum scarcely differs in any respect from Wolle’s X. tetracen- 
trotum, and must therefore be placed merely as & variety of the 
latter species 
10. Cosmarium cymatop.evrum Nordst. var. Arcarru (Roy & 
Biss.) nob. [Syn. Cosmarium Archerit Roy & Biss. in Ann. Scot. 
Nat. Hist. 1893, p. 42, t.i. f.5.] Long. 91 »; lat. 67 »; lat. isthm. 
24 yp. (Fig. 5. 
shes Penyghent, W. Yor 
pect cin from West Yorkshire were ntrediat between 
