50 HISTORY OF BRITISH PERNS. 



1. W. ilvensis, R. Brown. Pinnse oblong, deeply 



lobed. Plate III. fig. 2. 



2. W. hyperborea, R. Brown. Pinnse bluntly triangu- 



lar, lobed. Plate IY. fig. 1. 

 iv. LASTREA, PresL 



1. L. Thelypteris, PresL Fronds pinnate, not glan- 



dular ; sori sub-marginal on sub-contracted fronds. 

 Plate VI. fig. 1. 



2. L. Oreopteris, PresL Fronds pinnate, glandular 



beneath. Plate VII. 



3. L. Filix-mas, PresL Fronds sub-bipinnate or bi- 



pinnate, broadly lanceolate. Plate VIII. 



b. incisa. Larger, pinnules elongate, with deep 



serrated incisions. 



c. abbreviata. Smaller, pinnules contracted or 

 obsolete. 



d. multifida. Pinnse tasselled at the end. Plate 



VIII. upper figure. 



4. L. rigida, PresL Fronds bipinnate, without spinu- 



lose serratures, glandular. Plate IX. fig. 1. 



5. L. cristata, PresL Fronds pinnate or sub-bipin- 



nate, narrow linear, pinnules oblong. Plate VI. 

 fig. 2. 



