CHARACTERS OF TRIBES AND GENERA, 205 
falcatum (Sw.) (v v.); C. earyotideum (Wall.) (v v.); C. 
Fortunei, J. Sm. (v v.) (Ferns, Brit. and For.); C. Jug- 
landifolium, Kunze (v v.) (Amblia, Pr.); C. nobile, Kunze 
(Phaneróphlebia, Pr.) 
Oss.—T'he three first species are natives of India and 
Japan, the two latter of Mexico and Venezuela. 
Although I have not seen specimens of the Fern 
described in the “Species. Filicam” under the name of 
Polypodium (Cyrtomiphlebium) dubium, a native of Peru 
and Ecuador, I nevertheless believe it to be a species of 
Cyrtomium; and the reason for Sir William Hooker 
placing it in Polypodiwm seems to me to be consequent 
on the sori having through age or otherwise lost the 
indusium. : 
107.—PLEOCNEMIA, Presl (1836). 
Nephrodiwm Hook. Sp. Fil.; Polypodium, Gaud. 
Vernation fasciculate, erect, arboroid (vide Cuming).- 
Fronds bi-tripinnatifid, 12 to 15 feet long ; primary pinne 
1i to 2} feet long; ultimate pinnæ uniformly pinnatifid. 
Veins of lacins costeform ; venules forked, the lower ones 
arcuately and angularly anastomosing, forming unequal 
areoles next the costa; the exterior ones free. Fertile 
pinnules much narrower than the sterile. Sporangiferous 
receptacles medial on the free or anastomosing venules. 
- Sori punctiform in a row on each side of the costeform 
veins of the lacing. Indusiwm reniform. 
Type. Polypodium Leuzeanum, Gaud. 
Illust. Hook. and Bauer, t. 97 ; Moore Ind. Fil., p. 70, A ; 
J. Sm. Ferns, Brit. and For., fig. 71. 
 Orss.—This genus is founded on a single species, eg à 
owes its generic importance more to its gigantic habit | : E 
than to any real structural difference by which to^dis. _ 
