29S 



LASTURA DILATATA. 



Fig. 241.— Pinna towards the apex. 



Fig. 242. — Middle pinna. 



Fig. 243 — Basal pinna 



HowARDTJ, Monhnan. (Figs. 241, 242, 243.)— This is the 

 most remarkahle form of dilatata yet discovered; indeed it 

 may be said to present an entirely new arrangement hitherto 

 without parallel in the British Filices. In no other species, 

 excepting perhaps in Athyrium Filix-foGmina var. FieldicB and 

 Polystichum angulare var. Elworthii, has any approach to this 

 peculiarity of development been observed. And in the case of 

 FieldicB, a whole frond is requisite to give an idea of each separate 

 pinna of llowardii, therefore the peculiarities of the latter may 



