194, MESSRS. W. WEST AND G. S. WEST ON 
This plant possesses a great similarity of appearance to Spondylosium pulchrum, Arch., 
especially the bilobed form. The short connecting processes on the apices of the semi- 
cells are, however, sufficient to readily distinguish it from that species. Moreover, the 
lateral lobes of the semicells are different from those of any form of Spondylosiwm 
pulchrum we have seen. 
It also has a considerable resemblance to Streptonema trilobum, G. C. Wallich, but 
differs entirely in the nature of the connections between the cells, which are those of a 
true Desmidium. A gap of some considerable size is generally evident between the apices 
of any two contiguous cells. The filaments are enveloped in a thick mucous sheath. 
278. DESMIDIUM CYLINDRICUM, Grev., 1827 ; Ralfs, in Ann. & Mag. Nat. Hist. v. 1843, 
p. 373, t. 8. fig. 1.  Didymoprium Grevillii, Kuetz.; Ralfs, Brit. Desm. 1848, 
p. 57, t. 2. 
Hab. Paddyfield between Kosgoda and Urahaighasmahendai. 
279. DESMIDIUM GRACILICEPS, Lagerh. in Ofvers. af K. Vet.-Akad. Fórh. 1885, no. 7, 
p.238. D. quadratum, var. graciliceps, Nordst. in Wittr. & Nordst. Alg. Exsic. 
1880, no. 367. 
Long. 19-294; lat. 19-27°5 u; lat. apic. cell. 7:5-10 u; lat. isthm. 14°5-19,; crass. 
14-16 x. 
Hab. Paddyfields, Heneratgodha. ^ Paddyfield between Kosgoda and Urahaighasma- 
hendai. 
280. DEsMIDIUM COARCTATUM, Nordst. in Botaniska Notiser, 1887, p. 155; in K. Sv. 
Vet.-Akad. Handl. xxii. 1887, no. 8, p. 25, t. 2. fig. 3. 
Hab. Paddyfield between Kosgoda and Urahaighasmahendai. 
281. DESMIDIUM QUADRATUM, Nordst. in Act. Univ. Lund. ix. 1873, p. 49, t. 1. fig. 24. 
Long. 13:5-16 u ; lat. 21-22; lat. apic. 14°5-15 u; crass. 20 u. 
Hab. Paddyfields, Heneratgodha. 
A form with the cells relatively a little broader than in the type. 
Genus GyMxNozxGa, Ehrenb. 
289. GYMNOZYGA MONILIFORMIS, Ehrenb. in Bericht. Verh. Akad. Wissenschaft, Berlin, 
1840, p. 212. Didymoprium Borreri, Ralfs, in Ann. & Mag. Nat. Hist. xvi. 1845, 
p. 10; Brit. Desm. 1848, p. 58, t. 3. 
Var. GRACILESCENS, Nordst. in Bot. Notiser, 1880, p. 119; Wittr. & Nordst. Alg. Exsic. 
no. 367. | 
Hab. Paddyfields, Heneratgodha. Paddyfield between Kosgoda and Urahaighasma- 
hendai. 
Genus HYALOTHECA, Kuetz. 
283. HYALOTHECA DISSILIENS, Bréb. in Ralfs, Brit. Deem 1848, p. 51, t. 1. fig. 1. Conferva 
dissiliens, Dillw., 1806. 
