A. W. Evans — North American Species of Fndlania. 3 



niana and in one or two others, the first leaf of a branch sometimes 

 develops both lobe and lobule into water-sacs ; such a leaf is always 

 quite covered over by other leaves. 



It has already been noted that in sheltered places some species of 

 Fndlania may fail to develop water-sacs ; the lobule under these 

 circumstances is explanate and appears as a small, lanceolate, plane 

 or slightly concave process; transitional forms may frequently be 

 found between these explanate lobules and the typical inflated ones. 

 In every species, however, there are three leaf -modifications where 

 explanate lobules normally occur. These are (1) the leaves from 

 whose axils branches spring, (2) the pericha^tial bracts, and (3) the 

 perigonial bracts. In the first of these, the stylus is about as large 

 as the lobule and the whole postical lobe is very like an underleaf ; 

 occasionally the modified stylus bears a small tooth or secondar}^ 

 stylus on its inner edge. Even in this situation, although the stylus 

 always retains its modified form, the lobule is sometimes inflated as 

 in ordinary leaves. In the perichaetial bracts, the lobule, which is 

 often nearly as long as the lobe, is attached to it by a broad fold, 

 and the stylus, which can usually be distinguished even in toothed 

 bracts, appears on the inner edge of the lobule at some little distance 

 from the base ; occasionally the stylus is a segment of considerable 

 size. In the perigonial bracts the lobe and the lobule are subequal 

 and are connected by a broad fold to above the middle ; the bracts 

 are inflated so as to form hollow pouches for the antheridia, and the 

 stylus, which is carried up on the inner edge of the lobule, usually 

 remains minute. 



The perianth of Fndlania belongs to the hypogonianthous type 

 as described by Spruce.^ In this type of perianth there are three 

 keels, two lateral and one postical. The significance of this becomes 

 evident if we consider that a perianth is normally formed by the 

 coalescence of three floral leaves or " anthophylls," ^ including two 

 side-leaves and one undei-leaf. In case a species has flat leaves and 

 bracts, the anthophylls are flat, their united edges give rise to the 

 keels, and the perianth which results is triangular in section with an 

 antical keel and a flat, postioal face corresponding with the flat 

 underleaf. This is the "epigonianthous" type and is well repre- 

 sented by Lophocolea. In case a species has complicate leaves, the 

 anthophylls are folded, the folds and not the united edges give rise 



1 On Cephalozia, 5. 1882. The structure of the perianth is fully discussed in this 

 paper, but the points brought forward are so important that it has seemed advisable 

 to call attention to them again. - Spruce, 1. c, 3. 



