THE MORPHOLOGY OF THE LEAF OF FISSIDENS. 99 
angles to the latter when flattened out. All this is independent of 
the presence or absence of a nerve, for the leaf of F. hyalinus, 
to consist of only two planes, and not of three, as in the normal 
eaf of Fissidens. See in Lindenberg and Gotische’s ‘ Species 
Hepaticarum,’ the figures of Micropterygiwm, fase. 11, t. 21; and in 
Hooker’s ‘ Musci Exotici,’ the figures of (ottschea appendiculata, 
t. 15, and of G. Thouarsii, t. 48, which have leaves formed on the 
same plan as those of Micropterygium. 
It must be admitted that, in their normal state, lobed or deeply- 
cut leaves are rare in the true Mosses; yet we have examples o 
ch lobe ;—a somewhat ana te 
bilobed leaf of a Fissidens above described. e diligent observer 
ill call to mind frequent cases of Nesignaty from the ordinary 
sse e 
almost 
unoccupied field of research to any young bryologist desirous 
of distinguishing himself. 
