CHARACTERS. OF TRIBES AND GENERA. 277 
length, forming a continuous linear immersed sorus on 
each side of the mid-rib, and which become confluent. 
Type. Diclidopteris angustissima, Brackenridge. 
Illust. Brack., United States Expl. Exped. XVI. 135, 
£17; Moo Ind. Fil., p. 13, B. 
Ors.—The grass-like fronds of this Fern not — 
a line in width, renders it difficult to determine the exact 
nature of its venation. Careful examination induces me 
to draw up the above character, which agrees with that 
given by Brackenridge ; but in the “ Species Filicum " the 
line of sporangia are me as only occupying one side 
of the costa. 
Sp. D. angustissima, Brack. (Monogramma Junghuhnii, ` 
Hook. Sp. Fil. 5, t. 289, B; Bedd. F. S. Ind., pl. 210). 
Native of Ceylon, Java, Philippines and Polya 
Islands. 
85. PLEUROGRAMMA, Presl. (1836). 
Monogramma sp. Hook. Sp. Fil. ; Tænitis sp. Kaulf. 
Vernation fasciculate, erect, acaulose. Fronds cespitose, 
1 to 6 inches high, simple linear or forked, opaque, the 
upper portion concave or folded. Veins in the lower part 
simple, direct, oblique, the upper or fertile part absent. 
Sporangia produced in a line on each side of the costa, 
becoming confluent, forming a central sorus. 
Type. Plewrogramma linearis, Presl. 
Illust. Hook. and Bauer, Gen. Fil, t. 75, A; Schott., 
Gen. Fil., t. 17, under Cochlidium ; Moore, Ind. Fil, 
p. 14, A; Hook., Syn. Fil. t. 6, fig. 51, c. d. 
Oss.—This as a genus differs from Monogramma by the 
presence of lateral veins, and in the sporangia being pro- 
duced in a line on each side of, and close to, the mid-rib, — 
. also in having fasciculate vernation. 
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