Durand: The Genus Keithia 
9 
Phillips described the fungus as occurring on the upper side of 
the leaf, but in the twenty-five or more infected leaves examined 
it is hypophyllous without exception. I have seen no reference 
to other collections of this species before 1903. In that year a 
parasite of Juniperus 0 .vycedrus, from Corsica, was described 
under the name Didymascella Oxycedri, by Maire and Saccardo. 
I have not seen specimens of this fungus, but Maire, following 
the suggestion of Patouillard, later came to the conclusion that 
it does not differ from Keithia tetraspora. 
The erumpent ascomata remind one strongly of the pustules 
of some Puccinia. Sometimes as many as three ascomata may 
appear on a single leaf of the host. The spores are quite similar 
to those of K. thiijina, but there are four in each ascus, the septum 
is not quite so close to one end, and the walls are not pitted. The 
laciniate rupturing of the epidermis is distinctive, as well as the 
dark color of the hymenium. 
2. Keithia thujina sp. nov. 
Ascomata epiphyllia, erumpentia, orbicularia vel elliptica, pul- 
vinata, olivacea vel brunneo-olivacea, 1-1.25 mm. longa, .5 mm. 
lata ; epidermis supra integra non laciniatim decidens. Asci cla- 
vati, 80-100 X 18-20 /X. Sporae duae, brunneo-olivascentes, ellip- 
tico-piriformes, septo ad apicem anteriorem inaequaliter divisae, 
punctatae, 22-25 X Paraphyses furcatae, septatae, cla- 
vato-incrassatae, olivaceae. 
Ascomata epiphyllous, erumpent, at first buried beneath the 
epidermis which is lifted up, breaks around the margin, and finally 
falls away as an entire flap or scale, exposing the ascoma in the 
form of a cushion-like elevation. Ascomata circular to elongate- 
elliptic in outline, straight or curved, convex above, having the 
form of depressed cushions which are raised slightly above the 
surface of the substratum, .5 mm. broad, up to 1.25 mm. long; 
disk olive to olive-brown. Asci clavate, stout, 80-100 X 18-20 /x, 
opening by a pore, not blue with iodine. Spores 2, placed end to 
end, at first hyaline, finally becoming olive-brown, broadly ellip- 
soid or piriform-ellipsoid, the smaller end uppermost, at first con- 
tinuous, finally divided by a single transverse wall close to the 
distal end into two very unequal cells, epispore with minute pits 
over its whole surface, 22-25 X 15-16/x. Paraphyses branched 
below, septate, strongly clavate-thickened in the distal third, coher- 
ing, somewhat longer than the asci, 2-3 /x thick below, 5-8 /x thick 
above, olive. 
