336 
Gontotrichum ramosum (Thwaites) Hauck. This differs from 
G. elegans (Chauvin) Zan., by having cells which are green in 
color and longer than broad, instead of reddish, and as long as 
broad or shorter ; they measure .005-.008 X .008-.02 mm. I 
I found it at Quincy, Mass., in small quantity among other alge. 
Described in Hauck, Meeresalgen Deutschlands, p. 519. 
Calothrix Contarenii (Zan.) Born. and Fl. The filaments of 
this species considerably resemble those of C. scopulorum, but 
they are thinner and straighter, and so erect and closely packed 
as to resemble those of an /sactis. The surface of the frond also 
resembles /sactis, being dark green and smooth, thus easily dis- 
tinguishing it from C. pulvinata, which is equally densely packed, 
but has a spongy surface. I have found it at Revere Beach, 
Mass., growing in January and February a little above low water 
mark, on stones more or less imbedded in the sand. 
Calothrix eruginea (Kiitz.) Thuret. A species considerably 
resembling C. crustacea in color and habit, but smaller (filaments 
009-.0I, rarely .012 mm. diam.) and with fewer heterocysts. I 
found it at Cape Rosier, Maine, July, 1890, growing sparingly on 
fronds of Exteromorpha, Cladophora, etc., in a warm upper tide 
pool. Figured and described in Bornet and Thuret, Notes Algo- 
logiques p. 157, Tab. xxxvii. 
Calothrix fasciculata, Ag. The chief distingashing character 
of this species is the branching, which in mature plants takes the 
form of more or less dense, usually secund tufts, near the end of 
the filaments. I found it at Cape Rosier, Maine, in July, 1889, 
_ growing on rocks between tide marks. 
Enteromorpha micrococca, Kiitz. A small species, externally 
resembling a stunted form of Z. zztestinalts, but microscopically 
distinguished by irregularly placed, very small cells (.004-.005 
mm. diam.), arranged in no particular order, and by the rela- 
tively thick (.018-.02 mm.) cell wall. I found the plant at Mount 
Desert Island, Maine, in July, 1890, growing on exposed rocks 
near high water mark, in places where fresh water was running 
down. It is figured and described in Kitzing, Tabule Phy- 
cologicz, vol. vi, p. 11, Tab. xxx. 
Ulothrix implexa, Kitz. In making collections in the rather 
brackish water of the Mystic River, at Medford, Mass., in 
