116 Rhodora [JUNE 
some of which are usually elongated into slender cilia. The con- 
trasting characters in C. media are the following: the leaves are 
usually less deeply bifid, and the lobes, which are nearly always conni- 
vent, are more shortly pointed, being usually tipped with a single cell 
instead of a row of two cells; the perichaetial bracts are less deeply 
bifid, the lobes are less acuminate, and each usually bears on the outer 
edge a single broader and often blunt tooth; the mouth of the perianth 
is minutely crenulate or setulose from cells projecting singly. 
To these differences may be added a slight difference in the size of 
the leaf-cells. Schiffner criticises the measurements in Miiller’s 
description of C. macrostachya, where the cells are said to be 30-35 u 
in diameter. He notes that the original description gives a length of 
23-35 u and a width of 19-23 u, and he adds that he himself has found 
the cells to be about 20 u in diameter. He suggests that Müller may 
have made his measurements toward the dorsal base of the leaf, 
where the cells are invariably larger. From a series of measurements 
made by the writer on various specimens the cells in the upper part 
of the leaves were found to average about 21 X 18 u, while those in 
the basal region averaged about 30 u in diameter. In C. media the 
corresponding averages were 30 X 24 u and 35 y. 
In separating C. macrostachya from C. catenulata, the leaves Rees the 
perichaetial bracts are again of much importance. In this latter 
species the leaves are bifid to the middle or less with a narrow sinus 
and usually parallel acute lobes; the leaf-cells, which are about as 
large as in C. macrostachya, have somewhat thicker walls, and the 
perichaetial bracts are less deeply bifid with broader and less acuminate 
lobes, the margins of which are coarsely and irregularly dentate or 
spinose-dentate. C. catenulata rarely occurs in bogs, its usual habitat 
being rotten logs, while C. macrostachya, according to the information 
at hand, is confined to bogs. 
It will be seen from the foregoing notes that the recognition of 
sterile material of C. macrostachya or of male material with androecia 
of the simpler type is beset with difficulties, and it is probably unwise 
to attempt a positive determination in all cases. For this reason the 
writer has left unnamed several specimens which he suspects belong 
to C. macrostachya. None of the American specimens so far examined 
has shown androecia of the complex type described by Kaalaas. All 
the androecia studied, however, except a few very short ones, have 
shown small but distinct bracteoles, structures which are usually 
absent altogether from the androecia of C. media. 
