150 REVISION ОЕ THE Хоктн AMERICAN HYDNACEAE 
Plants chiefly terrestrial, mesopodous, often deformed, usually 
dark colored, brown, reddish to orange, sometimes whitish ; sub- 
stance fibrous, tough, sometimes compact, hard and woody, often 
in two layers the outer felt-like, soft, tomentose, the inner com- 
pact, hard; spores colored, coarsely tuberculate. 
The species of this genus were originally placed by Fries in 
his tribe Mesopus, section Lignosa, which was made to include 
all tough mesopodous species of the Hydnaceae. In 1878 Quélet * 
proposed to raise the whole group to the rank of a genus and sug- 
gested the name Ca/odon but failed to establish the genus accord- 
ing to present methods. Тһе next year Karsten, of. cit., inde- 
pendently took up the same group raised it to genéric rank and gave 
it the name Hydnellum making the proper binomial combinations 
which established the genus. Іп 1881 the last named author ор. 
cit. divided the group into the white toothed and the dark toothed 
forms and to the former gave the name Phellodon g. v. but for the 
latter, rejecting his own well established name Hydnellum, he took 
up Calodon proposed by Quélet, and gave it nomenclatural stand- 
ing ; in which he appears to have been influenced too much by 
his respect for others. As Karsten’s original work is logical, 
accurate, definite, and when he is not following others, is based 
on sound nomenclatorial principles, it seems right that his name 
should prevail. 
Synopsis of the Species 
Plants exuding red juice when injured. 
Plants fragrant, acrid, whitish or pale brown ; surface of pileus azonate, subeven, 
scarcely depressed. ; . H. Carb из. 
Plants odorless, mild, reddish-brown ; surface of pileus subzonate to azonate 
uneven, depressed to infundibuliform. 2. H. sanguinarium. 
Plants not exuding red juice when injured 
Plants small, less than 4 cm. wide ; pileus very thin. 7. Æ. zonatum. 
Plants larger, 3-15 cm. wide ; pileus thicker. 6. H. concrescens. 
color more or less uniform or irregu- 
Plants with more or less of orange in their color, often complicated, irregular. 
Plants large, more than 4 cm. wide, terrestrial. 8. М riform 
Plants small, less than 3 cm. wide, on cones. 
Plants with more or less of blue in their color, 
Plants large, more than 6 cm. 
ternally with blue, fragrant. 
9. H. conigenum. 
not complicated. 
wide, whitish, horizontally zonate in- 
‚ Suaveolens. 
*Clav. Hym. 196. 
