1917] 
MOORE—ALGAE OF DEVILS LAKE, NORTH DAKOTA 295 
species but found in practically all towings as well as asso- 
ciated with algae along shore. 
Genus MERISMOPEDIA Meyen 
Merismopedia convoluta Brébisson in Kuetzing, Spec. Alg. 
472. 1849. 
Merismopedia glauca (Ehrenb.) Naegeli, бай. einz. Alg. 
55. 1849. 
Merismopedia tenuissima Lemmermann, Bot. Centralbl. 76 : 
154. 1898. 
Of the three species of Merismopedia, M. tenuissima is by 
far the most abundant, being found in some twenty-six dif- 
ferent collections. M. glauca was found in but four samples, 
and M. convoluta occurred but once. 
Genus TETRAPEDIA Reinsch 
Tetrapedia gothica Reinsch, Algenfl. von Franken, 37. 1867. 
Rare. Sparingly found in two collections, one from towings, 
the other associated with Cladophora near the shore in front 
of the laboratory. This, so far as is known, is the first 
recorded collection of this genus in the United States, and it 
is likewise the first time the species has been found since its 
original diseovery by Reinseh in Germany. Archer! merely 
discusses the original description and plate, stating that he 
has never had the good fortune to encounter T'. gothica, and 
the reference by Forti? to Т. gothica being cited by Cook is 
an error. 
The genus Tetrapedia has long been recognized as one of 
the very few, if not the only member, of the Myxophyceae 
with figured cells—a condition strongly contrasting with the 
considerable number of Chlorophyceae which are charac- 
terized by definite but elaborately marked outlines. Tetra- 
pedia gothica is a compressed graduate cell with slightly 
rounded corners, with at first but a slight indication of the 
incision midway between each corner which ultimately divides 
tł Archer, Wm. Notice of the genus Tetrapedia. Quart. Jour. Mie. Sci. 
12: 354-358. 1872. 
? Forti, A., in De Toni, Syll. Alg. 5: 112. 1907. 
