212 CRYPTOGAMIA FIL1CES. [CI. 24. 



roundish -ovate, somewhat deltoid, crenate. Midrib flattened 

 beneath. 

 Mt. rocks. If • 6, 7. Like the last, but brighter green. Rib pale gr. 



3. A. marinum, 6. 392. (Sea S.) Frond oblong, pinnate ; leaflets 



ovate, oblique, serrated, obtuse ; unequal and wedge-shaped at 

 the base. 

 Clefts of marit. rocks. 2f . 7—10. Fr.firm, 3—9 in. Stalk dark- 

 col. Rib with a thick border. 



4. A. septentriondle, 15. 1017. (Forked S.) Frond three-cleft ; leaf- 



lets alternate, linear, jagged at the summit. 

 Alpine rocks ; rare. If . 6 — 10. Fr. innumer. in dense, dull green 

 tufts, 3 — 4 in. 



5. A. alter nifolium, 32. 2258. (Alternate-leaved S.) Frond pinnate ; 



leaflets alternate, wedge-shaped, erect, notched at the extremity. 

 Rocky mt.lf . 6 — 10. Fr. numer. 3 — 6 in. bright gr. Masses linear. 



6. A. Ruta muraria,3. 150. (Wall-rue S.) Frond alternately twice 



compound ; leaflets rhomboid-wedge-shaped, notched at the 

 extremity. 

 Rocks & old walls. If. 6 — 10. Fr. several, 3 — 4 m. like Rue-leaves. 



7. A. Adiantum nigrum, 28. 1950. (Black S.) Frond somewhat 



deltoid, alternately thrice-pinnate ; leaflets lanceolate, sharpish, 

 deeply serrated. 

 Shady pi. If . 6 — 10. Fr. \ f. dark shining green. Stalk purplish br. 



8. A. lanceoldtum, 4. 240. (Lanceolate S.) Frond lanceolate, doubly 



pinnate ; leaflets and segments obovate, deeply and sharply 

 toothed. Principal midrib not bordered. 

 Rocks in the S.lf. 6 — 10. Fr. scarce a span, grass-green. Stalks 

 shorter. 



9. A.fontdnum, Aspidium font. 29. 2024. (Rock S.) Frond linear- 



lanceolate, doubly pinnate; leaflets and segments wedge-shaped, 



deeply and sharply toothed. General and partial midribs bordered. 



Walls & rocks, rare. If . 6 — 9. An elegant little fern; 2 — 6 in. light gr. 



467. SCOLOPENDRIUM. Hart's-tongue. 



1. S. vulgdre, 16. 1150. (Common H.) Frond oblong, smooth; 



heart-shaped at the base. Stalk shaggy. 

 Moist shady sit. If. 7- 1 — Hj^ of a full grass green. 



2. S. Ceterach, 18. 1244. (Scaly H.) Frond pinnatifid; scaly at the 



back. 

 On rocks or old walls. If .4 — 10.3 — 6 in.slightly glauc; scales rusty. 



468. BLeCHNUM. Hard-fern. 



1. B. boreale, 17. 1159. (Northern H.) Frond smooth, pinnate, pec- 

 tinate ; leaflets linear, entire, scarcely dilated at the base. 

 Rough heathy gr. If . 7. Fr. tufted, lanceol. deep green, \%f. 



469. PTERIS. Brake. 

 1. P. aquilina, 24. 1679. (Common Brake.) Frond thrice pinnate; 



