This new species of Grimmia, alluded to in the preceding
Number, is generally found along with Grimmia torquata,
but is easily distinguished from it by the hoariness of its aspect,
when growing, and by the more slender stems, and less
twisted, hair-pointed leaves when in the hand.
In general habit, it resembles some varieties of Grimmia
trichopJujlla of this work (t. 100.); but the smooth capsule,
and short fruit-stalk, will prevent it from being at any time
confounded with it. There is only one other species with which
1 am acquainted, that may be compared with it, the G. apicu-
lata of H o p p e and H o i i n s o h d c h . This has a short, curved
seta, an ovate smooth capsule, and piliferous leaves. In habit,
however, it is very different, being a more robust, and much
shorter plant; and, when carefully examined, the operculum is
found to be nearly plane, with a rounded conical beak set as it
were upon it, instead of being convex, and shortly rostrate as in
our plant. The leaves also of G. apiculata are much less piliferous
than those of G. spiralis; the hairs are indeed scarcely
perceptible to the naked eye, and only occur on the uppermost
leaves. The teeth of the peristome afford a still more satisfactory
character, since they are perforated, and not cleft.
Fig. 1. Plants o f Grimmia spiralis, natural size. Fig. 2. ,4 plant, with capsule
and calyptra. Fig. 3. A lower leaf. Fig. 4. An upper leaf. Fig. 5. Sum-
mit o f a leaf Fig. 6. Capsule, with the operculum. Fig. 7. Summit ( f
the capsule, with the lid removed. Fig. 8. Two o f the teeth o f the peristome;
•—magnified.