MuRRiLL : The Boleti of the Frost herbarium 519 



Boletus cyanescens Bull. 



Six good plants are preserved. Frost has marked it " rare." 



Boletus uecorus Frost. 



Represented by three good specimens, which may be referred 

 to B. cdiilis. 



Boletus edulis Bull. 



One sheet contains two poor plants with their stems eaten 

 away by insects. On the other sheet is one very poor specimen, 

 which may be B. edulis, and a fine plant that is certainly B. 

 ornatipes. In a letter to Professor Peck, dated Nov. 27, 1874, 

 Frost says : " Have you Curtis' full description of Boletus retipes ? 

 From all I can gather it seems to me that the specimen I sent you 

 as such is the true one. What you describe as such I suspect is 

 a variety of B. edulis, it indeed does it exactly. If Bulliard's fig- 

 ure is the true species, then Sowerby's must be a variety, for they 

 are very much unlike in appearance but microscopically they are 

 the same species. What you describe is abundant here. Unless 

 I greatly mistake, it is another variety of Boletus ediilis. I am 

 familiar with all three of them." 



Boletus elegans Schum. 



This name is doubtfully assigned by Frost to a specimen from 

 Sprague and to one collected by himself, neither of which is very 

 well preserved. The former is B. luteiis and the latter is possibly 

 B. Ravenclii. 

 Boletus felleus Bull. 



One sheet contains a single large plant cut in half. It is well 

 preserved. The other sheet contains five plants, four of them 

 apparently B. ornatipes, and a single one, in the lower corner on 

 the right, B. felleus. 

 Boletus ferrugineus Frost. 



There is one sheet under this name containing five excellent 

 specimens collected in 1867 under oak trees near borders of woods. 

 A full description is written at the bottom of the sheet. I cannot 

 distinguish the species from B. felleus. (Plate 36.) 

 Boletus firmus Frost. 



Two poor plants represent this species, which is probably not 

 distinct from B. luridus Schaeff. In B. luridus the stem is usually 



