ASPLENIUM. 75 



separate them, those of lanceolatum being lance-shaped, or 

 tapering from near the middle towards the base, while those 

 of Adiantum-mgrum are always triangular, or broadest at 

 the base. The pinnse spread at nearly right angles with the 

 rachis, often, but not always, opposite, and have an ovate- 

 lanceolate form ; they are again pinnate, so that the frond 

 is bipinnate. The pinnules are of irregular form, often 

 obovate, or nearly so, sometimes unequally quadrate, but 

 always indented on the margin with deep, sharp teeth, the 

 larger pinnules being first lobed, and the lobes toothed, 

 the smaller ones simply toothed. 



The venation is tolerably distinct; the pinnules each 

 having a tortuous midvein, which produces forked venules, 

 one of the veinlets of which extends towards each serrature. 

 The sori have no very definite order ; they are at first ob- 

 long, and covered by an indusium of the same form, having 

 a lacerated free margin ; but as they become old the sides 

 become bulged out so as to give them a roundish form, and 

 the indusium becomes obliterated. 



This is rather a local species, being found only in the 

 southern and western parts of England, and in Wales, almost 

 always near the coast. It is found very luxuriant in the 

 Channel Islands, 



