36 CALIFORNIA ACADEMY OF SCIENCES. 



On leaves and twigs of Tetradymia canescens. Mt. David- 

 son, Nev., 7,000 ft., Aug. 2073. 



Very conspicuous from the contrast of the dark brown 

 sori, with the gray plant over which it is thickly scattered. 



Uromyces Nevadensis. 



I. II. Hymenium and Stylospores. Unknown. 



III. Teleutospores. Sori minute, aggregated in spots 1 — 4 

 mm. in diameter, covered for some time by the raised silvery 

 cuticle, pulverulent; spores dark brown, oblong or obovate, 

 smooth; pedicels hyaline, as long or longer than the spores, 

 deciduous, n 36—42 X 12—14. 



On living leaves of Primula suffrutescens. Near Lake 

 Tahoe, 6,000 ft., Aug. 3582. 



Uromyces Spragueae. 



I. Hymenium. iEcidium Spragueae. Hk. Covering the 

 whole leaf; peridia elongated, orange-red. 



II. Stylospores. Globose, pale brown, smooth. /* 24. 



III. Teleutospores. Sori irregular, pulverulent, mixed 

 with the iEcidium; spores oval, brown, marked with tortu- 

 ous furrows; pedicels short, hyaline, deciduous. iEcid. 

 fx 14 X 17. Teleut. 17—21 X 24—32. 



On living leaves of Spraguea umbellata. Sierra Nevada, 

 7,000 ft., Aug. 3370. 



Ustilago gayophiti. 



Spores dark brown, oval or globose, minutely echinu- 

 late; epidermis soon ruptured; spores in a powdery mass. 

 /U4— 18. 



Produced within the seeds of Gayophitum ramosissimum. 

 Summit of the Sierra Nevada, Aug. 3391. 



Peridermium gracile. 



Perithecia cylindrical, 3 mm. long, very slender, border 

 minutely fringed; spores globose, orange. /rl6 — 20. 



Scattered over living leaves of Sarcobatus vermiculatus. 

 Keno, Nev. August. 3568. 



