MYXONEMA 195 
Although one may be very sure of the distinctness of species, 
it is a very difficult matter to construct a good key. 
It is hoped 
that the following may be of some assistance, though it is very far 
from satisfactory. 
Synopsis of Species 
Forms in which opposite branching predominate 
Filaments 11-30 in 
n diameter, branches äi approximate. 
ower cells 1-2 times as long as broad, walls Mon branchlets usually 
short-pointed. . lubricum. 
Lower cells 2-5 times as long as broad, walls not sii branchlets more 
attenuate Ib. M. lubricum varians. 
Lower es 3-8 times as long as broad, branchlets nn 
. M. amoenum, 
Lower cells 4-8 times as long as broad, branchlets Ress 
3, M. ze iferunt. 
Lower cells scarcely longer than broad, branchlets thorn-like, a 
4. M. i rnm 
Lower cells 2-5 times as long as broad, much inflated. 
. M. ventricosnm. 
5 
Filaments 7-10, in diameter, branches less crowded, transitional form 
Lower cells 1-3 times as long as broad, branchlets tapering or setiferous 
6. M. tenue. 
Forms in which alternate branching predominates. 
se. 
i. 
7. M. thermale. 
Filaments ABort, cespit 
ing in thermal waters; diameter = > Di 
Growing in water of ordinary temper 
Diameter 6-8 u, ماش‎ us or short-pointed. 
8. M. nanum. 
Diameter 7-9 u, branchlets erect, attenuate or poa 
جس 2و0‎ 
Diameter 11-14 u, branchlets densely 02 setiferous. 
10. M. glomeratum. 
Filaments more or less elongated. 
Diameter 5-7 u. II. M. attenuatum. 
Diameter 8-11 u. M. stagnatile. 
Diameter 12-18 ۰ 3. AL subsecundum. 
MyxoneMA LUBRICUM (Dillw.) Fries, Syst. Orb. Veg. 343. 
Brit. Conferv. PM. 57. 1 March, 
1806. Agardh, Syn. Alg. Scand. 92. 181 7.(?) Lyngb. Tent. 
Hyd Das... 150. M. ee 
1819. Not C. /wbrica Roth. Cat. 
Bot. 3: 168. 1806 [= Zzrraspora lubrica]. 
Draparnaldia tenuis elongata Agardh, Syst. Alg. 57. 
1824. 
