I propose to publish additional supplements to both the Musci 

 and HrcrATie.K Exsiccatae which I have issued, as fast as I can 

 accumulate the needed specimens. The supplements to com- 

 prise 100 sets of 10-50 specimens each; and I take this op- 

 portunity to cordially invite the co-operation of all American 

 botanists. 



> 21P Liberal allowance will be made and due credit given, for 

 100 good specimens of any desired moss or hepatica. 



!3P Except in rare mosses and those difficult to obtain, the 

 Specimens should be large and ample. 



Up 3 Musci should be collected as soon as or a little before 

 the capsule matures, while the operculum is yet present. Some 

 species seldom or never fruit with us; these should not be neg- 

 lected. Hcpaticse in general are best collected late in the fall, 

 during the winter, or in early spring.— The Jungermaniw about 

 the time or a little before they send up the fruit-stalk. All are 

 best collected before they shed their spores. 



COE F. AUSTIN. 



