SPECIES FILICUM. 



SuBORi). IV.— PTERIDE.^.. 



Sori orbicular, oblong or linear, often continuous, mar- 

 ginal, situated at the apices of the veins or vcinlets. Jn- 

 volucre formed of the replicate margin of, but mostly differing 

 in texture from, the frond, taking the same shape as the sori, 

 membranaceous or coriaceous, covering the capsules or some- 

 times bearing them on its underside [Adiimtuui), opening 

 towards the axis of the frond or pinnule. — Tufted or creep- 

 ing Ferns, inhabiting various parts of the world, chiefly tro- 

 pical. Fronds simple or variously divided and compound. 

 Veins simple or forked or anastomosing. 



The present p^ioup corresponds, generally, with the Ptendea, J. Sm., 

 (excluding however all of his second section " Mrtasone,'' except Lomaria), 

 and almost entirely with the Adiantaccce of Presl. The name Pteridea 

 appears preferable, as expressing the most familiar Genus belonging to it. 

 To me it seems the Suborder cannot be advantageously divided into sec- 

 tions, the Genera of which it is composed passing too gradually the one 

 into the other to allow of it. 



1. Adiantum, L. 

 Adiantum, Linn. (Hook. Gen. Fil. tab. LXVl. B.) 

 Hewardia, J. Sm. (Hook. Gen. Fil. tab. LXXXIX.). 



Sori marginal, globose, reniform, oblong or linear, distinct, 

 or more or less confluent and continuous. Involucre the 

 same shape as the sori, formed of the reflexed margin of the 

 frond, on the underside, and bearing the capsules beneath, 

 which capsules have their origin upon veinlets running into 

 the involucre. Capsules stalked. — Ferns of temperate or 

 chiefly tropical countries, ahoundiug in the New JVorld, 

 with simple or pinnate or contpoundly divided fronds f never 



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