Ci) 
Grimmia rivularis Brid. Lake Lindeman. On rock near 
water-line. This plant has rather obtuse leaves, mostly some- 
what sinuate dentate above. The cell walls are less thick- 
ened and angular than in apocarpa, and the lower cells 
shorter rectangular and broader (593). 
Grimmia torquata Hornsch. Sterile specimens collected at 
Sheep Camp, Dyea Creek ; also at Lakes Lindeman and Ben- 
nett. The typical form has leaves more or less curved and 
twisted in various directions (596). In other specimens the 
leaves all twist about the stem in the same direction, present- 
ing avery rope-like appearance (598). The tufts may finally 
become of a dull, brownish-black throughout. Some small, 
brownish-green tufts only 1 cm. high were collected at Lake 
Bennett, apparently young plants. The leaves are short, with 
scarcely thickened or sinuous cell walls. Propagula, mostly 
at the base of the costa beneath, resemble those of ordinary 
torquata (599). 
Grimmia ovalis (Hedw.) Lindb. (Grimmia_ ovata 
Schwaegr.) Lake Lindeman and Dawson and at various 
intermediate points on the Yukon. Common (595). 
Grimmia tenuicaulis R. S. Williams, Bull. Torr. Bot. 
Club, 2'7: 316-317. 1900. Dawson on rather dry rock walls. 
Specimens not quite so slender as the type (590). 
Grimmia acicularis (Li.) C. M. (Racomitrium aciculare 
Brid.) Lake Lindeman (601). 
Grimmia microcarpa (Hedw.) C. M. (Racomitrium 
Sudeticum (Hedw.) B. & S.) Lake Lindeman. Limpricht 
states the leaf margin in this species consists of 2 layers of 
cells, distinguishing it from heterostichum which has only one. 
In these specimens the margin above consists sometimes of a 
double layer, on one side, at least (602). 
Grimmia heterosticha (Hedw.) C. M. (Racomitrium 
heterostichum Brid.) Lake Lindeman and Skagway. Leaf 
border of a single layer of cells (603). 
Grimmia fascicular’s (Schrad.) C. M. (Racomitrium 
Sasciculare (Schrad.) Bridel.) Lake Lindeman (605). 
Grimmia ramulosa Lindb. (Racomitrium microcarpum 
(Schrad) Brid.) Lake Lindeman (606). 
