HISTOEY OP INTEODUCTION OF EXOTIC PERNS. 39 
Hcmionites vestita, but described as having free veins. 
Whatever difference then may actually be in the 
character of the venation of these three species there 
can be no doubt but that they are closely allied and 
constitute a very natural group. I have always 
considered that Hemionites vestita does not well asso- 
ciate with true Hemionites, but now, having found 
two companions for it, I view them as forming 
a natural genus, to which I apply the name Ghrys- 
odium. I hope that ere long we may have the op- 
portunity of becoming better acquainted with them; 
their silky appearance renders them worthy of being 
added to our living collections. 
In the Fijis again. Ferns form a conspicuous feature 
in the vegetation. During a visit of only six months, 
recently paid to these islands by Dr. Seemann, for the 
purpose of exploring them and investigating their 
Flora, he collected specimens of about 800 species of 
plants, and of these one-seventh were Ferns, very 
few of which are yet known in our gardens. A few of 
the desiderata are worth mentioning, particularly the 
graceful Todea Wilkesiana, found by the collectors 
attached to the United States’ Exploring Expedition, 
and named by Mr. Brackenridge in compliment to 
Commodore Wilkes, who was in command of the 
expedition. It is spoken of by Brackenridge as the 
“ Little Tree-fern,” and as being not more than three 
or four feet high ; but Seemann found it in the moun- 
tains of Somosomo, where it grows as underwood, 
attaining seven feet in height, and often with several 
crowns. The stem is as slender as a walking-stick, 
and the fronds bipinnate, and about two feet in length, 
with the ultimate pinnules thin, but not so delicate or 
