8 
Mycologia 
in the description of Didymascella. The substance of the ascoma 
is soft and waxy when fresh. On the basis of these characters 
I believe that the affinities of Keithia are not with the Phacidia- 
ceae, with which European authors have associated it, but with 
the Stictidiaceae, to which the parasite on Tsuga was originally 
referred by Dr. Farlow. If this disposition is the correct one 
we have in Keithia a genus of strictly parasitic fungi in a family 
otherwise almost exclusively saprophytic. 
The genus may be characterized as follows : 
A genus of the Stictidiaceae parasitic on leaves of conifers. 
Ascomata erumpent, rupturing the epidermis either laciniately or 
in the form of a scale, bright-colored to dark. Spores 2 or 4, 
becoming olive-brown, divided into two unequal cells by a septum 
near one end. 
Synopsis of Species 
Spores 4 in each ascus. 
Epidermis ruptured laciniately, on Jnniperus. 
Epidermis ruptured in the form of a scale, on Tsuga. 
Spores 2 in each ascus, epidermis rupturing by a scale, 
epispore punctate, on Thuja. 
1. K. tetraspora. 
3. K. Tsugae. 
2. K. thujina. 
I. Keithia tetraspora (Ph. & Keith) Sacc. Syll. 10: 49. 1892 
Phacidium tetrasporum P. & K. Card. Chron. N. S. 14: 308. 
1880. 
Didymascella Oxycedri Maire & Sacc. Ann. Myc. i : 418. 1903 
(fide Maire, Bull. Soc. Myc. Fr. 21: 140. 1905). 
Hypophyllous, erumpent, ascomata at first buried beneath the 
epidermis, then breaking through and rupturing the epidermis by 
3-4 laciniae, seated in the midst of a small, circular, yellowish- 
brown spot; the pustule elliptical, .75-1 mm. long, .5 mm. wide; 
disk brownish-black. Asci clavate, 175 X 16-18 /x, apex rounded, 
not blue with iodine. Spores 4, uniseriate, at first hyaline, later 
becoming olive-brown, ellipsoid to piriform-ellipsoid, the smaller 
end occasionally prolonged to form a short beak-like projection, 
divided by a septum close to one end into two very unequal cells, 
the smaller being as often distal as proximal, 21-24 X 
Paraphyses cylindric, hyaline below, septate, 2-3 /x thick, the apex 
clavate, olive-yellow, 8-9 /x thick. 
On living leaves of juniper (/. communis, probably), Forres, 
Scotland, 1880, Rev. J. Keith. 
