Arthur: New Species of Uredineae 665 



Peridermium ornamentale sp. nov. 



Peridia in two rows along the under surface of the leaves, cylin- 

 drical, 1-2 fi long, at first bright orange, margin entire or erose ; 

 spores obovate, elliptical or nearly globose, 13-17 X 20-26 ft ; 

 wall thin, closely and finely verrucose. 



On Abies lasiocarpa Nutt., Mount Paddo, Wash., at about 

 6000 ft. alt., Sept. 4, 1900, W. N. Suksdorf, comm. by E. W. 



D. Hoi way. 



Gymnosporangium 



Sporiferous masses globose, pulvinate cinnamon-brown, 1-2 // 

 in diameter, solitary, or occasionally aggregated to form swellings ; 

 spores angular-oval or elliptical, not constricted at the septum, 

 22-26 by 41-52 ft, obtuse, usually narrowed toward each end; 

 wall uniformly thin ; pedicels hyaline, slender, firm, once to thrice 

 the length of the spore ; mycelium annual. 



Juniperus scopidoru 



May 



Aven 



Nelson. The type collection has been rather widely distributed as 

 G. clavipes, a species which it resembles, but from which it is 

 readily distinguished by the slender pedicels and general habit 



Roestelia Nelsoni sp. nov. 



Spermogonia epiphyllous, in clusters on yellow spots, promi- 

 nent, nearly black, very numerous. 



Aecidia hypophyllous in groups ; peridia long, 2-4 mm., linear, 

 somewhat curved, dehiscent by longitudinal slits toward the base, 

 apex subacute, remaining closed ; spores globose, 24-30 fi in 

 diameter, wall rather thick, chestnut-brown, minutely verrucose or 

 smooth, pores about eight, without order, prominent. 



On leaves of Amelanchicr alnifolia Nutt., Laramie Hills, Wy- 

 oming*. August K. 1 00 1. A. Nelson, no. 8597, communicated by 



F. S. Earle. 

 ' An inter 



sporangium Nelsoni 



In 



a letter Professor Nelson says : " This was collected in the exact 



spot where the Gymnosp 



There can be 



little doubt of the interrelation of the Roestelia and Gymnosporan- 

 gium" I have given the same specific names to both forms, hop- 

 ing that cultures in the near future will establish their identity. 



