142 
BEAUTIFUL FERNS. 
of the frond; of the former, toward the costa. In the areoles of 
the second series the sori are opposite : the indusium of the lower 
one free toward the costa ; of the other, in the opposite direction.” 
To this it may be added, that in some of the areoles the two sori 
meet and are confluent at the outer angle of the areole ; and in 
this case the two indusia are sometimes, though not always, 
united into one. The indusia of the areoles next the midrib are 
also often bent at an angle, and the two portions plainly united. 
It was from this condition of some of the sori that the genus was 
named Camptosorus (bent fruit-dot) ; and it is only on this pecul- 
iarity that the genus can be kept separate. 
The indusium is thin and delicate, composed of sinuous- 
margined cellules, and is more or less wavy along the free edge. 
The spores are ovoid, and have a crenated pellucid wing-like 
margin. 
Sir W. J. Hooker referred the Camptosorus, together with 
the species of Antigramma, and the very peculiar Mexican fern 
Schaffneria, to the genus Scolopendrium ; making the distinctive 
character of the genus to rest on the sori being “ in pairs, oppo- 
site to each other, one originating on the superior side of a vein- 
let, the other on the inferior side of the opposite veinlet or 
branch.” In this he was essentially anticipated twenty years by 
Dr. Endlicher ; to whom, however, Schaffneria was unknown. 
It is by no means impossible that future botanists will refer 
all these species to the old Linnasan genus Asplenium ; for it is 
now pretty generally admitted that differences in venation do not 
constitute valid generic distinctions, and a radicant bud on the 
