108 HISTORY OF BRITISH FERNS. 



of differences of another kind, less obvious, perhaps, at 

 tlie first glance, but doubtless of sufficient importance for 

 the separation of species. This book being intended for 

 the use of those who are only likely — at least Avhilst they 

 require its aid — to study the smaller group, ue shall point 

 out the minuter differences ^vhich serve to separate the 

 series of Crested Ferns into several recognizable forms. 



Lastrea crlstata grous ^ith very erect, narrow, oblong 

 fronds, whose deltoid pinnas are not quite divided down to 

 the central rib, and the lobes into which they are separated 

 are attached by the whole width of their base, and arc 

 oblong, with a rounded apex. The stipes is sparingly 

 furnished with broad, obtuse, membranous, whole-coloured 

 scales, and the caudex is creeping. 



Lastrea uUginosa has two or three sorts of fronds ; one 

 set, the barren earlier ones, has much resemblance to those 

 of the preceding, the other sets producing fructification, 

 being bipinnate at the bases of the pinnjc, the fronds 

 narrow-oblong, the lobes tapering to a point ; the scales 

 of the stipes are broad, blunt, and whole-coloured ; and 

 the caudex is creeping. This connects cristata with 

 s2)inulosa. 



Lastrea spimilosa grows erect ; has narrow, lance-shaped, 



