234 University of California Fiihlicatioiis in Botany [Vol. 6 



to the conditions in the Helvellales and Pezizales (Dittrich, 1898; 

 Dnrand, 1908; McCubbin, 1910). Schroter (1897, p. 62) places 

 Boletus under the Hemiangiocarpeae, in which by definition the 

 hymenium is enclosed at first but is later exposed. Hennings (1898, p. 

 108) states that certain of the "Boletaeeae" (Boletus) have their tubes 

 exposed from the beginning. Zeller (1914) makes a definite statement 

 that in the species with which he was working {Ceriomyccs Zelleri) 

 there were no traces of a veil present from the beginning. On the other 

 hand, I have found a very definite veil present in j^oung plants (10 

 to 15 mm. high) referred to two different species of Ceriomyces. In 

 both cases, however, the veil later entirely disappears, leaving no trace 

 either as an annulus on the stipe or as a fringe on the margin of the 

 pileus. 



From the above it would seem that the distinction between Cerio- 

 myces and Boletus based on the presence or absence of an annulus is 

 a question only of development and consequent persistence, as it is 

 also among various genera of the Agaricaceae. 



The distinction between Suillellus and Ceriomyces appears to be 

 merely a color character which disappears upon drying, and hence is 

 of no value in the determination of dried material. No traces of any 

 histological structures to which the red color might be referred, w^ere 

 found at the mouths of the tubes in Suillellus. 



As stated above, the distinction between Ceriomyces and Rostko- 

 vites is based chiefly upon the occurrence of glandular dots on the 

 stipe of the latter. As will be described later in this paper, structures 

 appearing to be very similar to the "glands" characteristic of Bost- 

 kovites were found upon the stipe of two forms of C. communis. 



In Boletus lute us, a representative of another genus, which, like 

 Rostkovites, is said to have glandular dots on the stipe, it was found 

 that the dots were of very different origin from that of the dots in 

 Rostkovites. 



Thus far I have been able to find two species of Ceriomyces in 

 California, namely, Ceriomyces commimis and Ceriomyces crassus, as 

 usually separated by the characters ordinarily used. From the study 

 of our Californian material it has seemed desirable to distinguish four 

 forms of C. communis and two forms of C. crassus, making six forms 

 belonging to these two species. Of eastern material I have had for 

 comparison three species of Ceriomyces, namely C. crassus, var. 

 separans, C. communis and C. auriflammeus. The plants from the 



