IMD BROOKLYN BOTANIC GARDEN MEMOIRS 
in the large size of the urediniospores which are only slightly flattened 
and are evenly verrucose-echinulate. The teliospores are much longer 
than those of IV. Medusae and are thickened at the apex. The charac- 
ter of the telial sori suggests that this species may be closely allied 
to M. albertensis. The sori are much larger as are also both uredinio- 
and teliospores. 
This species may be the same as that recently cultured by Weir 
and Hubert (Phytopath. 7: 108. 1917), who used telial material from 
P. trichocarpa referred to M. Medusae and obtained successful infec- 
tion on Larix europea and L. occidentalis. The actual material used 
for infection and the aecia resulting have not been seen by the writer 
but telial material sent by Dr. Weir from Montana agrees with the 
form described above. Aecia from the same locality on L. occidentalis 
agree in general with aecia of Melampsora Medusae and M. Bigelowit. 
The walls of the aeciospores are however somewhat thinner, I-2 y, 
and considerably thickened on opposite sides to 3-5 uw. They measure 
17-19 by 19-26 pw. Additional culture work, and a careful comparison 
of the resulting aecia with those of M. Medusae would be desirable. 
In any case, the morphological characters of the uredinial and telial 
stages are considered sufficient to warrant separation. 
19. Melampsora Piscariae sp. nov. 
O.and I. Pycnia and aecia unknown. 
II. Uredinia hypophyllous, scattered, rounded, 0.3-0.5 mm. 
across, early naked, somewhat pulverulent, orange yellow fading to 
whitish, ruptured epidermis conspicuous; urediniospores globoid to 
ellipsoid, 14-16 by 16-19 uw; wall colorless, 1.5—2 w in thickness, finely 
and closely verrucose-echinulate; paraphyses numerous, intermixed 
with the spores, capitate, smooth or with an occasional conical echinu- 
late marking, 32-64 4 long; heads 12-18 yu broad, wall uniformly 
thick, 2:5-4 pz: 
III. Telia not seen. 
ON EUPHORBIACEAE: 
Piscaria setigera (Hook.) Piper (Eremocarpus setigerus Benth.)— 
Corvallis, Sept. 20, 1914, 3308, type. 
Known only from the type locality. 
This species is referred to the genus Melampsora with considerable 
confidence in spite of the absence of telia, on account of the structure 
of the sorus, the character of the spores, and the presence of scattered 
capitate paraphyses. 
20. MELAMPSORELLA ELATINA (A. & S.) Arthur, N. Amer. Flora 7: 
[Li \TOO7: 
Aecidium elatinum Alb. & Schw. Consp. Fung. 121. 1805. 
