Seymour.] 183 [Feb. 6, 



Pacific Railroad. Beginning at St. Paul, Aug. 21, short stops and 

 hurried collections were made at various points until Sept. 23rd. 

 The dates and localities of collecting are as follows : 

 August 21, St. Paul, Minnesota, 



" 22, Brainerd and Detroit, Minnesota, 



" 23, Fargo, Dakota, 



" 25, Valley City, Dakota, 



" 26, Jamestown, " 



" 28, 29 and 30, Bismarck, Dakota. 

 September 2, Medora, Dakota, 



" 3, Miles City, Montana, 



" 4, Billings, " 



" 6, Livingston, " 



" 8, Bozeman, " 



" 11 and 12, Helena, Montana, 



" 15, Sand Point, Idaho, 



" 17, Wallula, Washington, 



" 19, Thompson Falls, Montana, 



'' 23, Minneapolis and Lake Minnetonka, Minnesota. 

 A few other localities are mentioned in the list, represented by 

 specimens picked up at points where the train stopped. Species 

 distributed in exsiccati from this collection are so noted. 



For aid in the determinations, I am indebted to Drs. W. G. 

 Farlow and P. Magnus and especially to the lamented Dr. Winter. 



CHYTRIDIACE^J. 



Synchytrium decipiens, Farl., on Amphicarpaza monoica, plenti- 

 ful ; Bismarck, Dakota. 



PEKONOSPOEE^l. 



Peronospora Halstedii, Farl., on Rudbeckia laciniata; Fargo and 

 Valley City, Dak. 



Peronospora ribicola, Schrt., Jahresbericht d. Schles. Gesellsch. 

 1883, p. 179; Plasmopara ribicola, Schrt. Krypt. Fl. Schles. Vol. 

 in, p. 238, where it is described as follows : "Rasen fleckenweise, 

 sehr locker, weiss. Conidientrager straff aufrecht, 2-4 mm. hoch, 

 mit 3-5 aufrecht abstehenden graden Aesten, meist in eine End- 

 spitze auslaufend ; Aeste grade, die untern mit 3-5 graden Seitenas- 

 ten ; Endastchen gmde, verschmalert, abgestutzt. Conidien kurz 

 elliptisch, 15-2Q//. lang, ll-13,u breit, mit flacher Papille. Keimung 



