Synopsis of New York Uncinulce. By Charles 

 H. Peck. 



[Communicated to the Institute, February 20th, 1872.] 



Genus Uncinula Lev. 



" Mycelium floccose ; perithecia globose ; appendages 

 rigid simple, bifid or dichotomous, uncinate, at length bent 

 upwards." — Berk. Outl. 



The species of this genus inhabit the living leaves of trees 

 and shrubs, and make their appearance late in summer or 

 in autumn. The mycelium, as in other Erysiphei, forms a 

 thin white webby film or coating which in some species 

 occupies the lower surface of the leaf, in others, both surfaces. 

 It may be quite dense and persistent or very thin and eva- 

 nescent, according to the species. The conceptacles in the 

 different species are from .003 to .007 of aninch in diameter. 

 The appendages in all our species are simple and generally 

 about equal in length to the diameter of their respective 

 conceptacles. Their hooked or coiled tips afford a very 

 convenient character by which to distinguish the species 

 of this genus from all other Erysiphei. 



The number of species inhabiting this state is unex- 

 pectedly large, seven being now known. Only three species 

 are credited to Great Britain, a country whose mycological 

 flora has been well investigated, and of these three, U. 

 adunca alone has been found in our State. 



Our species may be arranged in two groups or sections, 

 one group being characterized by its species having more , 

 numerous appendages than those of the other. The species 

 of this group generally have a more dense mycelium and 

 larger conceptacles than those of the other. These species 



