110 Rhodora [JUNE 
nation. This is the only New England record and must rest upon 
the specimens which Johnson saw. ‘These forms appear to differ 
from many specimens of M. mahabuleshwarensis that we have seen 
only in the absence of the additional apical process” (W. & G. S. 
West 1898, p. 296). 
19: MICRASTERIAS MAHABULESHWARENSIS Hobson, Ind. Desm., 
1863, pp. 168, 169, text fig.; Wolle, Desm. U. S., 1884, p. 112, pl. 
37, fig. 10; Johnson, New and rare Desm. U. S., II, 1895, p. 292; 
W. &. G. S. West, Brit. Desm., 1905, p. 121. M. americana, var. 
Hermanniana Wolle, Desm. U. S., 1884, p. 112, pl. 32, fig. 5. This 
species resembles M. americana but differs in the following points. 
Cells larger, lower and often the upper lateral lobes undivided, orna- 
mentation consisting of a series of acute denticulations bordering the 
interlobular sinuses, a central ring of four large granules above the 
isthmus, and often a single granule just above the isthmus. Length 
151-220 н, breadth 135-190 и, polar lobe 75-100 y, isthmus 19-22 и. 
N. H.: Meredith, rare (Johnson) Mass.: Lake Quinsigamond, 
Worcester (Stone); Carver's Pond, Bridgewater! The measurements 
are those given by W. & С. S. West, British Desmids. This species 
is closely related to M. americana if it is not а variety of it. It has a 
more southern distribution and is much more common in material 
from our southern states. It is rare in New England. 
20. Micrasrertas NompsrEDTIANA Wolle, Bull. Torrey Club, 
1884, p. 15; Desm. U. S., 1884, p. 113, pl. 52, figs. 3-5; Johnson, 
Bull. Torrey Club, 1895, р. 292, pl. 239, fig. 14; W. & С. 8. West, 
Some N. A. Desm., 1896, p. 239, pl. 14, fig. 4. Cells somewhat longer 
than wide, semicells three lobed usually, but developing two rudi- 
mentary lateral lobes occasionally; polar lobe spreading, divided 
laterally to form two arms of unequal length on either side, ends with 
two or more spines, basal lobes bifurcate, spreading, ends spinose, 
sinus deep, somewhat gaping, rudimentary lateral lobes varying from 
a small conical projection to a considerable lobe ending in a pair of 
spines; surface smooth. Length 134-191 м, breadth 115-171 y, 
isthmus 14-27 м. N. H.: Meredith, rare (Johnson). 
21. MICRASTERIAS MURICATA (Bailey) Ralfs, Brit. Desm., 1848, 
р. 210; Wolle, Desm. U. S., 1884, p. 118, pl. 31, figs. 4-7. M. muri- 
cata, var. tumida W. & G. S. West, Some N. A. Desm., 1896, p. 240, 
pl. 14, fig. 7. Euastrum muricatum Bailey, Castk. Desm., 1846, 
p. 126, figs. 1, 2 in text. Cells large, semicells divided laterally into 
