CHARACTERS OF TRIBES AND GENERA, ssi S 
side, their apices combined by a transverse, continuous 
marginal vein. Sort unilateral. Jndusiwm plane, free 
exteriorly. 
Type. Asplenium nidus, Linn, 
Ilust. Hook. and Bauer, Gen. Fil, t. 113 B.; Moore, 
Ind. Fil, p. 37 B.; J. Sm., Ferns, Brit. aud For., 
fig. 113. 
Oss.—This genus is distinguished from other simple- 
fronded Asplenie by the apices of the parallel venules being 
combined by a continuous marginal vein; it has a wide 
geographical range, being represented throughout India, 
the Malayan peninsula and islands, Southern China, Philip- 
pine, Sandwich, and other islands of the Pacific Ocean, 
extending to Australia and Norfolk Island in the south, | 
and Japan in the north. 
In Seemann's * Botany of the Voyage of the Herald" 
it is there recorded to have been found in one or two 
localities on the Pacific side of the continent of America, 
but this seems to be a mistake, as the Hookerian herba- Y 
rium contains no specimen of the genus from the American 
continent. | 
The simple form of the fronds does not afford much 
variety as regards difference that can well be explained in 
= words, yet they vary very much in size and texture, which 
in some instances seem to be normal to the special localities, 
and which gives the semblance to there being a number of ` i 
` distinct species, thirteen being enumerated by Fée, which 
in the ** Species Filicum " are reduced to seven; even this 
_ is more than can be satisfactorily determined by herbarium 
Specimens only. The cultivated examples of four forms 
known to me, although difficult to recognise as distinct 
When put in the herbarium, are, however, readily seen to 
y distinct species in the garden, and it is probable that 
