54 HISTORY OP BRITISH FERNS. 



9. A. Adiantum-nigrum, Linnaus. Frond bipinnate, 



triangular. Plate XII. fig. 2. 

 ix. CETERACH, Wittdenow. 



1. C. officinaruin, Willdenow. The only species. 



Plate I. fig. 1. 

 x. SCOLOPENDRIUM, Smith. 



1. S. vulgare, Symons. The only species. Fronds 

 strap-shaped, entire. Plate XV. fig. 1. 



b. polyschides. Fronds narrow, irregularly lobed, 

 fertile. 



c. crispum. Fronds much undulated at the margin, 

 usually barren. 



d. multifidum. Fronds multifid at the apex. 

 D. POLYPODIACE^ PTERIDE^E. 



xi. PTERIS, Linnteus. 



1. P. aquilina, Linnmis. The only species. 



a. vera. Inferior pinnules pinnatifid. 



b. integerrima. All the pinnules entire. Plate 

 XVII. fig. 1. 



xii. ADIANTUM, Linnaeus. 



1. A. Capillus-Veneris, Linnaus. The only species. 

 Plate XVI. fig. 1. 



