POLYPODIACE.E. 245 



acuminated point. Ultimate divisions oblong-lanceolate or oblong 

 and obtuse, uniting into an acuminate or obtuse crenate-serrate point. 

 Sori very crowded, and furnished with a linear-oblong indusium, the 

 apex of which is rounded, seated in a tooth or segment, margined by a 

 narrow wing on one or both sides, but usually on the outer side, termi- 

 nating in a sharp tooth. 



In var. a. the fronds are smaller, broad-ovate, and bipinnate, with 

 lance-oblong acuminate pinnae, and incisely lobed pinnules; the lobes 

 confluent into a blunt, dentate point. The indusium is quite linear and 

 attenuate at the base, the tooth on the outer side wanting. 



The great variety of forms which this species assumes, in the divi- 

 sion of the fronds and the length of the indusium, is more or less the 

 result of local causes ; those plants inhabiting arid and rocky places, 

 or growing on trees overhanging the scorching coral shores of these 

 islands, produce small, compact, and very coriaceous fronds, with an 

 indusium usually longer than in the individuals inhabiting forest 

 regions, where the atmosphere is humid ; in such localities the fronds 

 are much larger, flaccid, and more compound. Our var. h. although 

 a wide removal from the usual form of the species, closely approaches 

 the var. (3. latifolia of Hooker's Species Filicum ; but the fronds are 

 much smaller and the indusium longer. 



8. Davallia Tahitensis, Sp. Nov. 



D. rhizomate repente; stipitibus gracilibus angulatis hinc sulcatis; fron- 

 dibus coriaceis glabris late quinquangidari-ovatis bi-tripinnatis ; pinnis 

 ovatis acuminatis; pinnulis oblongo-laiweolatis obtusis basi cuneatis 

 inciso-dentatis apicem versus confluentibus ; indusio lineari-oblongo 

 truncato in dentem vel segmentum immersis, ala marginali angusta 

 indusium adcequante; sporangiis paullo exsertis. 



Hab. Tahiti, Society Islands : on trunks of trees, at the elevation 

 of 3,000 feet. 



Whole plant about a span high ; with a creeping rootstock. Fronds 

 ovate-five-angled, rather rigid, smooth and glossy on both sides, bi-tri- 

 pinnate; the divisions approximate; the primary ones somewhat 



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