-J20 FTLICES. 



found as high as 8,000 feet are densely tomentose beneath; while 

 others, collected on flat lands near the coast, are almost entirely 

 destitute of hairs, and, as would naturally be expected, more luxu- 

 riant in growth, with broader pinnules and segments than in the 

 mountain form. The former agrees with the state found in Oregon 

 and California, which also varies in the more or less tomentose nature 

 of its fronds. Kaulfuss refers the Californian plant to P. lanuginosa of 

 Bory and "Willdenow : if he is correct in so doing, then the P. lanu- 

 ginosa of Bory is not specifically distinct from the P. aquilina. 



43. N Y C H I U M, Kaulf. 



(Leptostegia, D. Don. Allosori Spec. Presl.) 



This genus is distinguished from Peris " by the fertile segments 

 being so narrow that the two sori are confluent, the free margins of 

 the two indusia conniving over the midrib, at length opening as it 

 were by a longitudinal suture;" the habit of the few species com- 

 posing it being also distinct. 



1. Onychium densum, Sp. Nov. (Tab. 13.) 



0. ccespitosum ; stipite semitereti hinc sulcata; fronde 3-4:-pinnafa 

 glahra ; pinnis pinnulisque confertis linearibus acutis subpetiolatis. 



Hab. Oregon; on the banks of Rogue's River ; rare. 



Plant tufted, from 8 to 9 inches high, with smooth, brown, glossy 

 stipes, about a span long, and a little thicker than a quill from a 

 sparrow's wing, nearly round, with a single shallow groove in front. 

 Fronds about 2 inches long, ovate in outline, smooth, quadripinnate 

 at the base and tripinnate towards the point; primary and secondary 

 divisions alternate and seated on a very short petiole, decurrent on 

 the rhachis. Pinmdes crowded, of a pale straw colour, varying from 

 3 to 5 lines in length, less than a line in breadth, linear, with a 

 stiff acute point and a cuneate base, the margin slightly revolute and 

 partially crenate. Indusium of a rather firm texture ; its margin a 



