16 MR. W. MITTEN—BRYOLOGIA OF THE SURVEY 
C. HETEROMALLUM, (Dicranum) Hedw. 
Hab. Cascade Mountains, Lyall. 
The genus Cynodontium of Hedwig, as described in the ‘ Species 
Muscorum,’ contains, besides C. capillaceum and C. inclinatum, two 
other species which have long since been removed to other genera; 
and although Distichiwm, applied by Schimper to the two species 
with distichous leaves, is more expressive so far as relates to them 
jn particular, yet it seems hardly possible to maintain a genus 
solely on this character, much less a natural family Distichie, 
when there is no appreciable difference in form or structure from 
the species allied to Cynodontiwm flexicaule, Schw., and the nume- 
rous species which agree with it in structure and habit. These, 
separated by Hampe from the other mosses usually referred to the 
genus Trichostomum, have been of late placed in the genus Lepto- 
trichum, Hampe; recently, however, it has been pointed out by 
Lindberg that this name was already in use for a genus of Fungi, 
and he proposed instead of Leptotrichum the name Diaphanophyl- 
lum, Lindbg.; but on looking back in the history of the species it 
would appear that there is no reason why Hedwig's genus, con- 
sidered as it must have been by Schwägrichen when he added 
C. flexicaule to it, should not be reinstated. The generic name 
Trichostomum, under which a number of species referable to Cyno- 
dontium have been arranged, cannot be employed, for reasons 
which will be stated elsewhere. If it be granted that the Diera- 
nacec are a group of species of which the genus Dicranum is the 
typical form, and which may contain a series of progressive deve- 
lopments from Archidium through Pleuridium, Bruchia, Garckea, 
into Cynodontium, the place of the last-named genus must be 
very close to Dicranum, and its only difference the absence of 
distinct alar cells. No generically distinctive character can be 
drawn from the peristome, which in point of structure is alike in 
all the species of the family, and attains its highest known deve- 
lopment in Dicranum. The structure of the leaves is nearly the 
same in all, exeepting in the genera Didymodon and Holomitrium, 
in which the cells become shortened in the upper portions and 
thus approach to the Trichostoma. The aggregation of the cleisto- 
carpous genera Archidium and Pleuridium in the same group of 
genera with Dicranum is a breaking up of the old idea of a sepa- 
rate family for the Phascoid mosses ; but it may be observed that 
the sole difference between Plewridiwm and Cynodontium is the 
absence of a deciduous operculum; and that all the other Phascoid 
genera are referable to other more highly developed families is 
