18 



The appendages are so unique and the forks so conspicuous that 

 it seems impossible a mistake should be made in identification. In 

 some instances, when the division is near the end, an approach to 

 Microsphmra is apparent, but the characteristic curve oi' coil of the 

 tips, leaves no room to doubt the proper generic position. 



U. inacrospora, Peck, Trans. Albany Inst. VII, p 215. — 25th Rep. 

 N. Y. State Mus. p. 96. 



Amphigenous. Mycelium conspicuous, abundant. Perithecia 

 large, 110-165 ji, wall tissue soft, reticulations very small, usually 

 5-10 fi, and rather obscure; appendages very numerous, 50 or more, 

 hyaline, slender, smooth, usually shorter than the diameter of the peri- 

 thecium, tips closely coiled, not enlarged. Asci several, 8-10. Spo- 

 ridla 2, large, 20 x 30-35 fi. 



On Ulmus fulva, U. Americana, U. alata, Ostrya Virginica. 



Rather common east of the Rocky Mountains. On the last 

 named host (collected by Tracy in Wisconsin) the fungus is undoubt- 

 edly the same as that much more commonly found on elms. 



It differs sufficiently from European specimens of U. Bivonm, 

 Lev. on Ulmus campestris (Thiim. Mycoth. Univer. No. 755). In 

 these latter the perithecia are smaller (80-90 ^), and the reticulations 

 are much larger (10-15 fi), and more distinct. The fewer (less than 

 20) appendages are stouter, somewhat roughened and conspicuously 

 swollen at their tips. The usually four asci each contain two sporidia 

 about 30 /I long but narrower than in U. macrospora. 



U. intermedia, B. & C. appears from description to be the same 

 as U. macrospora. 



U. parvnla, C. & P. Erysiphei of the U. S. Journ. Bot. 1872. 



Amphigenous. Perithecia usually small, 90-100 p., rarely 135 //, 

 delicate, reticulations distinct, small and regular, averaging about 10 «; 

 appendages 60-100, delicate, slender, hyaline, commonly shorter than 

 the diameter of the perithecium. Asci 5-7, broadly elliptical. Spo- 

 ridia 5-8, mostly 6, about 20-25 fi long. 



On Celtis occidentalis. Prom the Atlantic coast to Washington 

 (Seymour). Not apparently abundant, but often collected from widely 

 separated localities. 



Distinct from U. polychmta, B. & C, on same host. Washington 

 (State) specimens have perithecia of larger size than usual, attaining 

 rather more than 125 /i, while 100 fj. seems to be about the extreme 

 for eastern specimens. 



U. polychaita, (B. & C.) 



Erysiphe polychista, B. & C. Grev. IV, p. 159. 

 Uyicinula Lynckii, Speg. Fung. Arg. ir, p. 17. 

 Pleochcsta Curtisii, Sacc. & Speg. Fung. Arg. II, p. 44. 

 UncimUa polychesta^ Rav. F. Car. IV» No, 68, 



