CHARACTERS OF TRIBES AND GENERA, 179 
87.—XirnorrEnis, Kaulf. (1824). 
Grammitis sp. Sw. ; Polypodium sp., Hook. Sp. Ful. 
Vernation sarmentose, slender, sub-ascending. Fronds 
contiguous, sub-fasciculate, 2 to 6 inches high, linear, 
dentate-serrate, or pinnatifid below, sub-entire, and plieate 
or nearly plane above. Veins simple, free, very short. 
Sporangia borne on the short venules, forming oblong sori 
conniving with the mid-rib, included in the plicate apex of 
the frond. 
Type. Grammitis serrulata, Swartz. 
Illust. Hook. Gard. Ferns, t. 44; Hook., Exot. Fil., 
t. 78; Moore, Ind. Fil, p. 14 B.; J. Sm., Ferns 
Brit. and For., fig. 48. 
Oss.—Distinguished from Plewrogramma by the sori 
being oblong and diverging from the mid-rib, but becoming 
confluent. 
Sp. X. serrulata, Kaulf. (v v.) ; X. myosuroides, kont", 
X. Jamesoni, Hook. Second Cent. Ferns, t. 14. 
= Oss.—In the “ Species Filicam " the above three species 
` are considered as forms of one only. As regards X. Jame- 
soni (of which I have not seen specimens), it is said that 
the texture is so rigid that the thread-like mid-rib remains 
after the pinne fall. This singularity appears to me to be 
sufficient to mark itas a distinct species. They have a wide 
geographical range through Tropical America, the West 
Indies, Sandwich Islands, and also West Tropical Africa ; 
X. serrulata being one of the few Ferns common to both 
. Continents. 
88.—GnawurrIS, Sw., in part (1800). 
Polypodium sp. auct, and Hook Sp. Fil. 
— Fernation fasciculate, erect, acaulose or sarmentose. | 
Fronds linear-lanceolate, entire, rarely sub-pinnatifid, plane, 
