156 JUNGERMANNIACEAE 
in company with Chiloscyphus polyanthos rivularis and Рета 
rivularis, Sisson, Siskiyou Co., July, 1894 (no. 34). 
The stream, which is formed by a great spring beside the rail- 
way track about three fourths of a mile north of the village of 
Sisson, is said to maintain nearly a uniform volume throughout the 
year, and as plants were found wholly under water in the last of 
July and the first of August, it is probable that their submersion is 
permanent, : 
The above species was referred at first, uncritically, to Scapania 
undulata and listed under that name in Erythea (4: 49. 1896). 
From S. undulata, however, it is certainly very distinct in the ob- 
scurely complanate branches, in the sometimes 3-ranked, often 
more deeply lobed, erecto-patent, never alate-carinate, leaves, with 
more or less squarrose tips, and in the obovate rather than round- 
trapezoidal ventral lobes. The interpolated unlobed leaves stand 
sometimes in about the general position of dorsal or ventral lobes, but 
more often squarely subtend the ventral surface of the stem. They 
can doubtless be explained in some cases, from the point of view 
of ontogeny, by the separation of the normally united lobes, but in 
other cases this hypothesis seems to find little justification. Ме 
have noticed one or two three-lobed leaves out of hundreds exam- 
ined and in such the complete disjunction of the most ventral lobe 
would have thrown it nearly into the place of an underleaf. 
When the leaf-lobes are subequal it is often difficult to distinguish 
between the dorsal and ventral aspects of the stem, especially if 
further confused by the presence of the supernumerary entire 
leaves. From stems of such a character as this, however, may 
Spring young shoots in which the leaves are regularly distichous 
and acutely complicate, in the ordinary Scapania fashion, with the 
ventral lobes twice the size of the dorsal. In the axils of the upper 
leaves are sometimes to be found numerous short clavate para- 
physes, unicellular or of two or three oblong cells in a lineal series. 
жн аге indebted to Herr К. Loitlesberger for pointing out (i 
1.) that the leaves of our plant are “ two cells thick in the middle,” 
a texture which he has never found in submerged Scapania undulata. 
_ t is possible that. the species deserves to be separated сепег- 
ically from Scapania, but in absence of perianth and sporogonium, 
we can do no better than refer it to a genus with which it surely 
has very much in common, 
