Drs H o o k e r and T a y l o r , or into the excellent Flora Sco-
tica of tlie former author; and it is owing to this omission that
the present representation has its origin. It was not until the
whole impression was in the hands of the colourer, that I
ascertained it to be described in English Botany. The figure,
however, which is there given, is so incorrect, and withal
so destitute of the peculiar character of the plant, that it is
confidently hoped the public will pardon the repetition. To
the late Mr D ic k s o n is due the merit of having added this
species to our Flora. Mr D r u m m o n d , however, after a long
interval, has re-discovered it, and transmitted specimens in a
perfect state to Dr H o o k e r and myself. The calyptra being
decidedly dimidiate, has occasioned its removal from the genus
Trichostomum to that of Didymodon, with which it altogether
agrees in habit, and to which. Dr H o o k e r has indeed
long considered it to belong.
It is a remarkable fact, that, in examining the sporules of a
capsule not quite mature, though of fiill size, the greater number
were observed to be furnished with pedicels, as represented
at Fig. 9.
Figs. 1. Didymodon glaucescens, nat. size. Fig. 2. I^orvcr leaf. Fig. 3. Upper
ditto. Fig. 4. Theca with the operculum. Fig. 5. Theca with the peristome.
Fig. 6. Portion o f the peristome. Fig. 7. Calyptra. Fig. 8. Sporuks from
a mature theca. Fig. 9. Sporules with pedicels from an immature theca.—
All except Figs. I. more or less magnified.