: CHARA CTERS OF TRIBES AND GENERA. 
> Eier the costal areoles always vacant. Receptacles 
x punctiform on the combined apices of the excurrent vein- 
. lets. Sori round, transversely one to two serial, naked. 
| "Type. Polypodium aureum, Linn. 
Illust.— Hook. and Bauer, t., 112. Moore Ind. Fil., P. 58, 
figs. 1—3. J. Sm. Ferns. Brit. and For, fig. 9. Hook. 
Syn. Fil., t. 5, fig. 48, g. ; 
Oss.— This is a well-marked genus, containing about 
half a dozen species, all natives, of the West Indies and ` 
Tropical America. In general habit it resembles Gonio- 
phlebium, but is distinguished by the sori being borne on ` 
the combined apices of at least two excurrent veinlets, and ` 
by the costal aeroles having no free veinlet. 
Ex.—P. aureum (Linn.),(v v.), P. sporodocarpum ( Willd.), 
(v v.), P. areolatum (Willd.), (v v.), P. pulvinatum (Link), 
_(vy.), P. decumanum (Willd.), P. dictyocallis (Fée), (v “ig 
Sect. 3.—PLEURIDEX. 
12.—Pievripium, Pres] (1836). 
Polypodium, Sp. auth., Hook. Sp. Fil.; Phymatodes, section 
z Pleuridium, Presl in part. 
Beene short, or elongating. Fronds simple, vii, 
 papyraceous, or coriaceous, from 6 inches to 2 feet i i 
length, thick marginate. Primary veins costæform, elevated, 
Straight. Venules compound anastomosing. Receptacles 
 compital, punctiform. Sori round or oblong, EEN one 
| Or two serial between the primary veins. 
— "Type. Polypodium erassifolium, Linn. — 
Tllust .— Schott. Gen. Fil. t. 1 (Anexetum). Hook. a 
Ü Bauer, Gen. Fil, t. 99. J. Sm. Ferns, Brit. and 
SC 22, 
vm pe arranges the species. of Canon 
