POLYPODIUM, § DIPTEBIS. 99 



tains, Miss Atkinson. Malay Peninsula and Islands, Blume, Wallich, Sir IV. 

 Norris, Cuming, n. 218 and 2G3, De Vriese and Teijsmann, n. 17, 63. Tropical 

 Pacific Islands, Milne, Ilarvij, Braclcenridge. Norfolk Island, All. Cunningham. 

 — The most distinct of all the Z>/-y«a;-ia-group, the fertile fronds being strictly 

 pinnated. 



§ 12. DiPTERis. — Fronds binate, generally ample, each portion repeatedly di- 

 chotomously flahelUform ; costce prominent, dichotomous, two branches run- 

 ning parallel in the long broad segments {one ?n P. Lobbianum). Vc7iation pro- 

 minent, very copiously and compoundly anastomosing wit hareoles oft en four -sided. 

 Sori small, compital, very copious, often arranged in series. Species mostly 

 tropical Indian or Pacific. — Ucn. Dipteris, Reinw., Moore. Sp. o99-401. 



399. P. (Dipteris) JVallichii, Br. ; caudex creeping clothed 

 with appressed copious black hard subulato-setaceous scales 

 wrinkled at the back, stipites 1-2 and more feet long 

 smooth and polished, fronds coriaceous 1-2-i feet long and 

 much wider than long dark-green above pale-yellowish fer- 

 ruginous beneath, flabelliform bipartite into two nearly equal 

 broad-cuneate portions which are palmately and dichoto- 

 mously divided, ultimate segments 6-8-10 inches long H-2 

 inches wide oblong acuminate, cost?e from the summit of 

 the stipes dichotomously branched through the disk of the 

 frond, a single pair runs through each terminal segment 

 connivent at the apices, venation manifest prominent be- 

 neath, all the costae are united by transverse flexuose cos- 

 tules, these by a longitudinal flexuose vein through the middle 

 into two nearly equal series of costular areoles then again 

 into lesser ones all subquadrangular, sori small superhcial 

 copious scattered in the areoles but generally in series more 

 or less perfect and accompanied by a resinous or gummy sub- 

 stance. — Br. in Hook, and Grev. Ic. Fil. t. 168-9. Wall. Cat. 

 n. 287. Metten. Polypod. p. 119. Drynaria, J. Sm. Dip- 

 teris, Moore, hid. Fil. p. 341. Polyp, macrocheiros. Wall. 

 Herb. 



Ilab. India: Pundoa mountains, Wallich ; Assam, Khasya, Boutan, Griffith, 

 Hooker fil. and Thomson, Thos. Lobb. — A remarkable and noble species, named 

 after the most distinguished and liberal of Indian botanists. 



400. P. (Dipteris) Horsfieldii, Br. ; caudex creeping rather 

 stout clothed with rigid black appressed subulate scales 

 wrinkled at the back, stipites 1-2 feet and more long, fronds 

 coriaceous 1-2-3 feet long and much wider than long flabel- 

 liform dark-green al)ove very glaucous beneath bipartite the 

 two portions palmately and dichotomously divided (as in the 

 preceding species) l^ut the ultimate segments arc more acu- 



