156 ACOTYLEDONS. F1LICES. 



5. A. alternifolium^ fronds pinnate, pinnules alternate lanceo- 

 lato-cuneate toothed at the apex, lower ones trifid and tooth- 

 ed. E. B. t. 2258. A. germanicum, Willd. 



HAB. Sunny rocks in the south of Scotland, about two miles from 

 Kelso, on the Tweed, Dickson. (In Switzerland it is quite an al- 

 pine plant.) 



6. A. Ruta-muraria, fronds bipinnate at the base, pinnules eu- 

 neate obtusely toothed at the extremity. Light f. p. 665. 

 E. B. 1. 150. 



HAB. Walls and the fissures of rocks, frequent. 



7. A. Adiantum nigrum, fronds bipinnate, pinnae oblongo-lan- 

 ceolate acute, pinnules oblong ineiso-pinnatifid, the segments 

 toothed at the apex, sori at length confluent. Lightf. p. 666. 

 E.B.t. 1950. 



HAB. Banks in shady places, and fissures of rocks, frequent. 



6. SCOLOPENDRIUM. 



Sori linear, transverse, scattered. Involucre double, occupying 

 both sides of the sorus, superficial^ and opening as it were by 

 a longitudinal suture. 



1. S. vulfrare. E.B.t. 1150. Asplenlum Scolopendrium, 



Light/, p. 660. 



HAB. Shady, rocky, or stony places. 

 Frond ligulate, acute, entire, cordate at the base. 



7. PTER1S. 



Son* continuous, linear, marginal. Involucre formed of the in- 

 flexed margin of the j'rond opening interiorly. 



1. Pt. crispa, sterile fronds bipinnate, pinnules pinnatifid, the 

 segments obovato-crenateinciso-dentate at the extremity, fer- 

 tile fronds bipinnate tripinnate below, pinnules linear oblong 

 rather obtuse entire narrow at the base. E. B. t. 116. Os- 

 munda crispa, Light f. p. 655. 



HAB. Among rocks and stones in the Highland mountains. Ben-na- 

 Caillich in Skye, Lightf. Salisbury craigs, Mr. Stuart. Birnam 

 hill and near Cluny, Mr. Arnott. Goat-fell, in Arran, sparingly ; 

 on Ben Nevis, plentifully, Mr. Murray. Western Lomond Hill, 

 Fifeshire j and near New Abbey, in Galloway, Maugh. 



2. Pt. aquilina, frond tripartite, branches bipinnate, pinnae li- 

 near-lanceolate, superior undivided, inferior pinnatifid, the seg- 

 ments oblong obtuse*. E. B. 1. 1679. Lightf. p. 657. 



' I am happy in having the opportunity of publishing here some remarks 

 upon the structure of the fructification of this plant, which have been kindly 

 communicated to me in a letter from Thomas Smith, Esq. of the Temple, 

 London. They allude to a real involucrwn distinct from that formed by the 

 involution of the margin of the frond. " This," Mr. Smith says, " will be 

 found exactly opposite to that which is seen on the edge of the frond, and, 



