190 NEMATOPHYCES, 
Stigeoclonium protensum. (Dillw.) Kutz. Tab. Phyc.111,,t. 8, f. 2. 
Pale green, cespitose, slender ; filaments and branches long 
drawn out; cells almost cylindrical, equal or twice as long as 
their diameter; terminal cell extended into a colourless bristle ; 
branches usually scattered, rarely in pairs, with the extremities 
cuspidate, piliferous. 
Sux. Cells -015 mm. diam. 
Rabh. Alg. Eur. iii., 378. 
Draparnaldia condensata, Hass. Alg. 122,t.11,f.1. Ann. 
Nat. Hist. xi., 429. 
Conferva protensa, Dillw. Conf. t. 67. Gray. Arr. i., 303. 
In slow streams. 
Plate LXXIV. fig. 1. Filament of Stigeocloni ot - a, 
zoospores X 400 diam.; 8, branchlet of form called S. irregulare x 
400 diam. 
Stigeoclonium nanum, (Dillw.) Kutz. Spec. p. 352. 
Filaments alternately branched; branches abbreviated, a 
little attenuated upwards, obtuse, not piliferous; cells equal or 
a little shorter than their diameter, in the upper part equal. 
Sizz. Cells 008 mm. diam. 
Rabh, Alg. Eur. iii., 380. 
Draparnaldia nana, Hass. Alg. 124, t. 10, f. 3. 
Draparnaldia sparsa, Hass. Ann. Nat. Hist. xi., 428. 
Conferva nana, Dillw. Conf. t. 30. 
In streams (the Wye). 
The following are Dillwyn’s remarks on this species :—“‘ The minute- 
ness of the filaments, which in length seldom much exceeded a line, 
prevented me from ascertaining their nature so fully as I could have 
wished. Their colour is pale brown, tinged with green, sub-diaphanous 
under the microscope. They appear to consist of a single stem, beset 
at uncertain distances with alternate branches, which are again clothed 
with short, simple, solitary ramuli, placed at small distances from each 
other, most commonly alternate, although sometimes two or more 
together are disposed on the same side. All of them are finely acumi- 
nated; the dissepiments are very apparent, and divide the filament into 
joints, all of equal size, of which the length is about double the thick- 
ness. To the naked eye this plant appears, when taken from the water, 
like a mere mass of decaying vegetable matter. Its extreme minuteness 
might fairly induce a suspicion whether it is in reality anything more 
than the seedling of some known Conferva. It adheres to either glass 
or paper.” 
Plate LXXIV. fig. 2. Filament of Stigeoclonium nanum  K 400 
diam., figured from Dillwyn’s original specimen. 
