FILICES. 109 



crown, arranged shuttlecock -fashion, dying in autumn. Stipes 

 stout or rather stout, thickened immediately above the base, chan- 

 nelled on the anterior face, variable in length, thickly clothed at the 

 base with lanceolate or ovate-lanceolate persistent brown scales, and 

 rather sparingly above with lanceolate or strapshaped mostly deciduous 

 brown scales. Lamina erect or spreading, elliptical-oblanceolate or 

 narrowly elliptical-oblong or lanceolate-oblong, more or less attenuated 

 towards or abrupt at the base, subbipinnate or subtripinnate or tri- 

 pinnate ; ultimate segments crenate or serrate or inciso-serrate ; ultimate 

 veins running into the teeth. Sori distributed over the whole of the 

 frond, placed mostly on the anterior side of the first anterior branch of 

 the veins running into the ultimate segments, oblong and more or less 

 crescent-shaped or recurved at the apex, so as to be hooked or even 

 horseshoe-shaped, rarely round. Indusium subpersistent, strongly 

 fimbriate on the free margin, of the same form as the sori, the shape 

 of which indeed is determined by that of the indusium ; rarely it is 

 fugacious or apparently wanting, in which case the sori are round 

 and naked. Spores yellowish or yellowish-brown, nearly smooth, 

 with a few small remote bluntish tubercles, rarely with numerous 

 tubercles. 



Tar. a. genuinum. 



Fronds spreading or arching backwards. Stipes short, one-sixth to 

 one-third the length of the lamina. Lamina flaccid, elliptical oblanceo- 

 late or broadly elliptical, conspicuously convex-sided, tapering from 

 above the middle to the apex, and longly attenuated towards the 

 base ; pinnse decreasing in size downwards until the lowest pair is 

 often not more than twice as long as broad ; ultimate pinnules or 

 segments oblong or oval-oblong or lanceolate, flat. Spore yellowish, 

 nearly smooth. 



Tar. /3. erectum. 



A. Pihagticuni, ' BotTi' Moore, Handbk. Brit. Ferns, ed. ii. p. 136. 



A. convexum, Nevcm. (part) Pliyt. 1851, App. xiii., and Hist. Brit. Ferns, ed. iii. p. 212. 



Fronds suberect. Stipes often rather long, from one-sixth to one- 

 half the length of the lamina. Lamina rather firmer than in 

 var. a. oblong elliptical or oblong, subparallel-sided, tapering more 

 towards the apex than towards the base, which is rather abrupt ; 

 pinnae not decreasing so much in length downwards as in var. a, 

 and the lowest pair being many times longer than broad ; ultimate 



