REVISION OF THE NoRTH AMERICAN HYDNACEAE 137 
wide, subglobose to ovoid, coarsely tuberculate, often appearing 
irregular, dark colored usually brown to fuscous, occasionally 
ale. 
The first genus ever organized out of the group of plants now 
known as the Hydnaceae was established by Dillenius, Catalogus 
Plantarum circa Gissam nascentium 188, pl. 1. 1710, and was 
called Erzmaceus. The plant described and figured in the above 
cited reference was undoubtedly the one now known as Hydnum 
repandum 1. In 1735* Linnaeus, Systema Naturae, proposed the 
name Hydna as a substitute for Erizaceus Dill. Later the name 
was changed to Hydnum and finally it appeared in the Species 
Plantarum 1753 with four species listed under it, namely, Z. 
imbricatum, H. repandum, H. tomentosum and H. auriscalpium. 
According to the principles here followed, although Æ. imbricatum 
(the type of Sarcodon) was the first species mentioned, А. repan- 
dum, the original Erzzaceus of Dillenius, becomes the type of the 
genus Hydnum. 
The genus, as thus originally established by Dillenius and 
reéstablished by Linnaeus, was so natural and clearly marked by 
its awl-shaped teeth that it has never been called in question, and 
the only confusion that has ever arisen concerning it has been 
from a failure to follow an obviously fundamental principle of 
nomenclature. Even if one does not accept the modern doctrine 
of generic types, it must be admitted that at least some one or more 
of the species given under a genus by its author at the time of its 
publication must be regarded as such type, otherwise there is no 
ground for generic stability and the very expression “ generic 
type ” is meaningless. It is to be observed that the genus Hya- 
num as established in 1753 by Linnaeus consisted wholly of 
stipitate plants, and it is absurd to restrict the name to resupinate 
forms. 
The toothed hymenium was so obvious and distinctive a char- 
acter of these plants that it became customary to refer everything 
possessing this feature to Hydnum until the genus became loaded 
* In my ‘ Historical Review of the Genera of the Hydnaceae," Bull. Torrey 
Club 29 : 438, it was stated that the name Hydna was proposed in 1737. had not 
then seen a copy of the rare first edition of the Systema Naturae. I have to thank Dr. 
Barnhart for calling my attention to Fee's reprint. From this it appears that the facts 
are as stated in the text. 
