CHARACTERS OF TRIBES AND GENERA. 
tomosing. Receptacles punctiform or oblong linear, pro: . 
duced on the confluence of two or more excurrent arcuate 
veinlets, terminating in the medial areoles. Sori transverse 
uniserial, furnished with indusiform peltate scales. 
Type. Polypodiwm percussum, Cav. 
Illust. Hook and Bauer, Gen. Fil, t. 18 ; Moore Ind. 
Fil., p. 62, figs. 1, 2, 8, 4; J. Sm., Ferns, Brit. and 
For., fig. 12. 
Oss.—In my genera of Ferns (1841) I made the genus 
Pleopeltis, as founded by Humboldt, a section of the genus 
Phlebodium of R. Brown, but now considering that habit 
assists to define groups of naturally allied species, and as 
the species of Phlebodium and those of the present group 
(Pleopeltis) differ entirely in habit, I deem it best to retain 
the two as distinct genera. 
In order to show the different views entertained W 
Pteridologists respecting the limits of genera, I may here 
ention that Mr. Moore, in his “ Index Filicum,” includes 
under the genus Pleopeltis, the whole, or in some cases 
part only, of the species of no less than twenty-five genera 
‘of authors, of which he makes eight sections, which in 
most cases differ not only in habit, but also possessing other 
Special characters ; I am, therefore, induced to — them 
as distinct genera. 
The following are the wert species that represent 
Pleopeltis as here restricted. The greater number are 
first are natives of the Eastern Hemisphere. 
$ Fronds smooth, glabrous. (Lepisorus, J. Sm. 1846). | 
>. lineare ( Thunb.) ; (P. nuda, Hook. Ez. Fla, t.63) (v v.) ; 
excavata (Bory); (P. nuda, Hook. and Bauer, Gen. Fil, 
8, non Hook. Ez. Fl.) e WW 
natives of the West Indies and Tropical America, the — aru 
