25 

 abundant and the reticulations are larger and more evident. 

 M. semitosa, B. & C. Grev. IV, p. 160. 



Epiphyllous. Mycelium persistent. Perithecia few, somewhat 

 aggregated, 90-100 p., delicate, reticulations regular and distinct, 

 about 10 fi; appendages 12 or more, about equal to the diameter of 

 the perithecium, colored throughout, paler toward the tip, or the color 

 stopping at a distinct line like a septum, 3 or 4 times dichotomously 

 branched, primary branches long, others short, tips obtuse, not re- 

 curved. Asci several. Sporidia small, 10 x 15 p.. 



On Gephalanthus occidentals, rare, Carolina (Curtis) ? Illinois 

 (Waite, Pammel). 



In the specimens examined, the number of asci varied from four 

 to six, and the sporidia in each seemed to be about six, but were poorly 

 developed This fact is evidently characteristic of the species, though 

 in some other species the sporidia mature quite as tardily. 



M. Vaccinii, (Schw.) 



Erysiphe Vaccinii, Schw. Syn. N. Am. No. 2491. 



Microsphere/. Vaccinii, C. & P. Krysiphei of the U. S. in Journ. of Bot. 1872. 



Amphigenous. Mycelium thin and delicate, often evanescent, or 

 sometimes abundant, persistent. Perithecia variable, often small. 

 80-90 //, or large, 110-120 f, fragile; appendages 6-20, hyaline, 

 smooth, slightly colored at base, 2 or 3 to as many as 6 times the 

 diameter of the perithecium, branching various, usually 3 or 4 times 

 forked, with the tips truncate or bifid, not recurved, occasionally more 

 ornate, with tip distinctly recurved. Asci 4-8, small and broad, 

 about 40 x 55 //. Sporidia 4-6, small. 



On Gaylussacia resinosa, VacciniumPennsylvanicum., V. C ana- 

 dense, V. vacillans, V. corymbosum, Andromeda, and Epigma repent. 

 Evidently not often collected. Massachusetts (Seymour) to Illinois : 

 New Jersey (Arthur). 



This is a variable species, not only in the character of the myce- 

 lium, but in the length and branching of the appendages. In most 

 cases the tips are swollen and not at all recurved. It has sometimes 

 been referred to Erysiphe because the appendages were not found to 

 be forked, but careful search has revealed some forked tips in all the 

 specimens at hand, including those named Erysiphe by others. More- 

 over, in all cases the appendages are stiff and somewhat straight, not 

 having the floccose character of typical Erysiphe species. Peck re- 

 ports that he has never seen what has been called Erysiphe Vaccinii 

 Schw., on Epigcea repens in fruit in New York, but a specimen col- 

 4 



