The most frequently consulted works were those of Prof. 

 Chas. H. Peck ; his Boleti of the United States is the best and 

 only good reference to go by for our Boletus family. 



The spore measurements were from Professor Peck's works. 

 The illustrations were all taken by myself from fresh specimens 

 with a Hawkeye camera, I was not enough of an expert in 

 photography to accomplish the ratio of comparative sizes which 

 are given in the text. 



No doubt this volume will be criticized by those who know 

 more of this branch of Botany than I do : but it is consoling 

 that it is not the only scientific work which has passed through 

 the same ordeal. 



I am ever so thankful to the contributors to whom I had 



referred above. 



Wm. Herbst, M.D. 

 Trexlertown, August /, i8gg. 



CORRIGENDA. 



The reader will please make the following corrections with 

 a pencil on the pages and places indicated : 



Page 17. — 2. Acomycetes should read : 2. Ascomycetes. 



Pa^e 19. — 2. Uridineae should read : 2. Urediiiae. 



Pa.«e 52. — Agaricus serotinoides, Pk., should read P. serotinoides, Pk. 



Page 123. — Under B. subtomentosa. in the second line under Spores 

 read " yellow cracked Boletus " instead of *' red cracked Boletus." 



Page 175. — IE. sanibuci should read M. sambuci. 



Page 206. — Genus Ph\ tophora should read Phytophthora. 



Plate facing page 38 : For Tricholoma terriferum read Tricholoma 

 personata, and for Tricholoma personata read Tricholoma terri- 

 ferum. 



Plate facing page 56 : For Entoloma rhodopolius read Entoloma 

 clypeatus. 



