356 THE DEVONIAN FOSSILS OF CANADA WEST. 
a synonim) was perfectly obsolete. And as the name is decidedly 
inappropriate, I hold that it cannot be restored now. 
I shall, in conclusion, direct attention to the uncharacterized genus, 
Megalomus. This name was proposed by Professor Hall in the 3rd 
volume of the Pal., N. Y., as a generic appellation for a species 
which is a true Cyrtodonta. I have ascertained that it has the same 
curved anterior teeth, and although I have not seen the posterior teeth, 
there is not the least doubt but that they do exist. Now, it might be 
thought that dJegalomus, having priority over Cyrtodonta, should 
take its place. I contend that this would not be the correct or the 
just course. In Professor Hall’s description he has “overlooked” 
the generic characters, and only given those which are specific. All 
that he has described is not sufficient to constitute a genus. The 
best proof of this is, that the author cannot recognize it himself, as 
he has since described two other genera, Palearca and Megamboma, 
which, if retained, would include Megaiomus. I have been the first 
to describe correctly and illustrate this genus under a name that is in 
no respect inappropriate, and I have a right to retain that name 
against those which are objectionable or not founded on an intelligible 
generic description. I further consider Megalomus an inconvenient 
name, because it so closely resembles Megaloma, a genus of Gastero- 
pods. 
Sub-genus VANUXEMIA. 
Fig 128. 
Fig. 128.— Vanuaxemia Bayfieldii—Billings, shewing the interior of left valve. 
This sub-genus was proposed by me, to include those species of 
Cyrtodonta which have the beaks terminal, or nearly so, and the 
