1912]  Evans,— Notes on New England Hepaticae,—X 219 
7. CHILOSCYPHUS RIVULARIS (Schrad.) Loeske, Verhandl. Bot. 
Ver. Prov. Brandenburg 46: 172. 1904. Jungermannia pallescens, 8 
rivularis Schrad. Syst. Samml. Krypt. Gew. 2: 7. 1797. Chiloscy- 
phus polyanthus, 8 rivularis Nees, Naturgeschichte der europ. Le- 
berm. 2: 374. 1836. Submerged in brooks, sometimes exposed to 
the air through the drying up of the water. New Hampshire: Shel- 
burne (W. G. Farlow); Waterville (Miss Lorenz). Vermont: Jerico 
(A. W. E.); Newfane (A. J. Grout). Massachusetts: Lynn, Reading, 
and Woburn (C. C. Kingman). Rhode Island: Cranston (J. F. 
Collins, 1851a). Connecticut: New Haven and Ledyard (A. W. E.); 
Bolton, East Haven, Portland, and Stafford (G. E. Nichols); Canter- 
bury (Mrs. Hadley); Plainfield (J. L. Sheldon). Widely distributed 
in North America, the known range extending from Newfoundland 
west to British Columbia and south to Pennsylvania and California. 
The present species, as understood by Schiffner, is apparently the 
most abundant representative of the genus in North America as well 
as in Europe. In its most typical condition the shoots, which are 
about half as large as in Ch. fragilis, develop numerous widely spread- 
ing branches, the leaves are deep green in color and longer than broad, 
while the leaf-cells are small, averaging about 25 u in the middle of the 
leaf. The perianth is much the same as in Ch. polyanthus, and the 
calyptra is exserted at maturity. Apparently perianths are never 
produced when the plants are completely submerged but only when 
they are more or less exposed to the air. This fact is brought out by 
Schiffner, who also calls attention to the changed appearance of the 
plants under these circumstances. The branches, for example, are 
less numerous and spread more obliquely, while the leaves become 
more crowded and acquire a paler and more yellowish hue. In other 
words these subterrestrial modifications (forma subterrestris Schiffn.) 
show a striking resemblance to ordinary Ch. polyanthus. According 
to Müller they actually represent Ch. polyanthus and he therefore 
considers Ch. rivularis a mere environmental form and unworthy of 
recognition as a species. Schiffner, on the other hand, maintains 
that his position (which is also that of Loeske) is correct and that the 
subterrestrial forms of Ch. rivularis merely resemble Ch. polyanthus 
superficially without losing their specific characteristics. He points 
out, among other things, that they still retain their small leaf-cells 
although he admits that the cells are not quite so small as in typical 
submerged conditions. He describes, however, a new submerged 
