164 CHARACTERS OF TRIBES AND GENERA. 
Oss.—The last named is a native of Mexico, Cuba, and 
other parts of Tropical America, the other five are natives 
of India, Malayan Peninsula and islands, and J apan. 
74.—PraTYLOMA, J. Sm, (1841). 
Pellea, sp. Hook. Sp. Fil. 
Vernation uniserial, erect or decumbent, acaulose. Fronds 
pinnate or bipinnate, smooth, 1, 2, or more feet high ; 
segments articulate with the rachis. Veins forked, their 
venules free, their upper portion sporangiferous, forming 
oblong sori, which become laterally confluent, forming a 
broad compound, continuous, marginal sorus, sub-included 
under the revolute indusseform margin of the segments, 
which in some is very narrow. 
Type. Adiantum paradozum, R. Br. 
Illust. Hook. and Bauer, Gen. Fil, t. 115, A; Hook. 
Fil. Exot., t. 21 and 48; "Moore Ind. Fil, p. 52 B; 
J. Sm. Ferns, Brit, and For., fig. 92. 
Ons. —Hitherto the species of this genus stood under 
the tribe Pteridew, but the sporangia being borne on free 
veins, and as they agree in habit and general aspect with 
Llavea, Y therefore deem this section their natural place ; 
but I must remark that several species of the genus Bella 
have a strong claim of relationship with Platyloma, and 
are only distinguished from the latter by the sporangia 
being borne on the combined apices of the veins, forming a 
continuous sorus on the axis of the indusium, as in true 
Pteris. 
This genus -consists of about a dozen species, widely 
distributed, being represented in Australia, New Zealand, ; 
South Africa, as also tropical and temperate North America. —— 
