CHARACTERS OF TRIBES AND GENERA. 179 



87. XIPHOFTERIS, Kaulf. (1824). 

 Grammitis sp. Sw. ; Polypodium sp,, Hook. Sp. Fil. 



Vernation sarmentose, slender, sub-ascending. Fronds 

 contiguous, sub-fasciculate, 2 to 6 inches high, linear, 

 dentate- serrate, or pinnatifid below, sub-entire, and plicate 

 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. 



OBS. Distinguished from Pleurogramma by the sori 

 being oblong and diverging from the mid-rib, but becoming 

 confluent. 



Sp. X. serrulata, Kaulf. (v v.) ; X. myosuroides, Kaulf. 

 X. Jamesoni, Hook. Second Cent. Ferns, t. 14. 



OBS. In the " Species Filicum " 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 pinnae fall. This singularity appears to me to be 

 sufficient to mark it as 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. GRAMMITIS, Sw., in part (1800). 

 Polypodium sp., auct., and Hook Sp. Fil. 

 Vernation fasciculate, erect, acaulose or sarmentose. 

 Fronds linear-lanceolate, entire, rarely sub-pinnatifid, plane, 



