1 1
Pi’ ;
III
portion or apiculus evidently depending for its length upon that
of the operculum, to the internal apex of which it is attached,
often rather permanently, as in the genus Systylium. When
the theca is moist, none of the columella is visible, except the
apiculus ; but when dry, tbe dilated portion becomes exserted
from tbe shrinking of the theca, and it may then be termed
capitate, as in the Splachna.
Weissia splachnoides bears the greatest affinity with S y s tylium
splachnoides of H o r n s h u c h . In the fructification,
this takes place in a remarkable degree, the only essential diife-
rence residing in the teeth of Systylium, which are geminate,
—a difference, nevertheless, which must maintain their separation
as long as generic distinctions are derived from the peristome.
Fig. 1. A tuft o f W. splachnoides. Fig. 2. Plants with young fructification,
both nat. size— The following are all magnified. Fig.*3. Theca with the
lid. Fig. 4. Theca with the half-grown calyptra. Fig. 5. Theca with the
calyptra becoming dimidiate. Fig. 6. A leaf. Fig. 7. Portion o f a leaf,
shewing the reticulation. Fig. 8. Theca dissected, with the lid still retained
by the columella. Fig. 9- Peristome, the lid having fallen from the apex o f
the columella. Fig. 10. Portion o f the peristome. Fig. U . Sporules. Fig. 12.
A theca represented in its dry state.
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t h .