434 Arthur and Kern : Peridermium 



I. Aecia from a limited mycelium, hypophyllous in two rows 

 on yellow spots occupying part or usually all of the leaf, deep- 

 seated, small, 0.2-0.3 mm. in diam., 0.5-1 mm. high, cylindrical ; 

 peridium colorless, dehiscence at apex, cells overlapping, only 

 loosely joined, readily falling apart, rather slender, inner wall 

 moderately verrucose, 4-5 p thick, outer wall smooth and thinner ; 

 aeciospores broadly ellipsoid, 15-18 by 1 8-27 fit, wall colorless, 

 thin, about 1 fit, finely and evenly verrucose. 



On Tsnga canadensis (L.) Carr. {Abies canadensis Michx.), 

 Buffalo, New York, no date, G. W. Clinton (specimen in herbarium 

 of U. S. Dept. Agric), Shelburne, New Hampshire, September, 

 1882, W. G. Farlozv (in Ellis, N. A. F. no. 1023)1 Utica, New 

 York, December 9, 1886 and February, 1887 , Daniel Batchelor ; 

 Wellesley, Massachusetts, June, 1889, Grace E. Cooky (in Seym. 

 & Earle, Econ. Fungi no. 223a); Manchester, Massachusetts, 

 July, 1890, IV. C. Sturgis (in Seym. & Earle, Econ. Fungi no. 

 22 jf); Blacksburg, Virginia, July 14, 1897, W. A. Murritt (speci- 

 men in herbarium of the N. Y. Bot. Garden) ; near Tibb's Run 

 reservoir, West Virginia, June 15, 1904, John L. Sheldon. 



27. Peridermium elatinum (A. & S.) Kunze & Schmidt, 



Deutschl. Schwamme 14.1. 18 17 



Aecidium elatinum Alb. & Schw. Consp. Fung. Nisk. 121. 1805. 



0. Pycnia epiphyllous, few, scattered, punctiform, inconspicu- 

 ous, subcuticular, not extending much into walls of epidermis, in 



section depressed-hemispherical, small, 100-130/i broad, 40-50 /* 

 high. 



1. Aecia from a perennial mycelium, dwarfing the young 

 shoots and forming witches' brooms, hypophyllous, forming two 

 irregular lines, deep-seated, wholly dropping out of the substratum 



at maturity, roundish or irregularly oblong, large, 0.5-1 mm. 



across, bladdery, soon open by falling away of the upper part ; 

 peridium colorless, dehiscence irregular, cells with thin inner and 

 outer walls ; aeciospores broadly ellipsoid or nearly globoid, 14-18 

 by 16-28 /i, wall colorless, thin, 1-1.5 fi y closely and rather finely 



verrucose. 



On Abies balsamea (L.) Mill, Ripton, Vermont, no date, E. 

 Braincrd (in Ellis, N. A. F. no. 1437) ; Andover, Massachusetts, 

 no date, Joseph Blake, communicated by P. L* Ricker ; Riverhead, 

 Bay of Islands, Newfoundland, September 12, 1885, A. C. Wag- 

 home ; La Pointe, Wisconsin, 1896, L. 5. Cheney (specimen in 



