Some fungi which are found on a considerable number of hosts of the same order, 

 as Cystopus candidus, might, perhaps, better have been placed together in a group 

 just under the name of the order, and it was originally intended to adopt such an 

 arrangement, for it is evident that the frequent repetition of the name of a common 

 species tends to interfere witli rather than facilitate the use of a host-index. But we 

 found it difficult to manage such an arrangement without spending more time than 

 was at our command. It is to be regretted that we were not able to indicate in 

 some way whether the fungi occur on the leaves, stems, or fruits. But, in main 

 cases, the facts could not be ascertained without much additional labor, while, in 

 others, the habitat can readily be inferred and, in still others, the fungi may be ex- 

 pected to occur on any of the organs. As it is, the index is sufficiently complicated, 

 and it was found impossible to add other distinguishing characters except at consid- 

 erable extra expense. 



As the printing of the first part has required considerable time, there are several 

 additions from current literature which could not be included. It is hoped that the 

 remainder of the index will be issued during the coming winter, and it is intended to 

 have additions and corrections of the present part given in an appendix to the second 

 part. By an error in paging, the fungi on Magnolia sp. indet. were not placed in 

 the proper order. They are here given on a supplementary sheet, and will be in- 

 cluded in their proper place in the appendix of the following part of the index. 



W. G. FARLOW 

 Cambridge, July j/, 1888. 



