100 Prof. Owen on the genus Mylodon. 
X.—Reply to some Observations of Prof. Wagner on the genus 
Mylodon. By Prof. Owen, F.R.S. 
To the Editors of the Annals of Natural History. 
GENTLEMEN, 
In the very excellent report on Mammalogy, in 1842, by. Prof. 
A. Wagner, which forms part of the first valuable volume just 
published by the Ray Society, there occur two criticisms, to which 
satisfactory replies were given soon after they appeared, but which, 
bemg reproduced mm an English translation, without comment, 
might mislead the zoological student on the points to which those 
criticisms refer. 
The first (p. 60) relates to the genus Mylodon, and Prof.Wagner 
cites the late lamented and talented naturalist Dr. Harlan as 
having ‘ proposed, in 1835, the name Aulaxzodon or Pleurodon 
for Mylodon ;” adding, ‘ the latter of these two is evidently better 
than Mylodon, which signifies nothing else than grinder.” | 1 
have shown in a letter, which the editors of the ‘ American 
Journal of Science’ did me the honour to insert in the 44th vol. 
(January—March 1843) of them most useful periodical, that the 
fossil remains to which Dr. Harlan proposed to attach the names 
Aulaxodon or Pleurodon belong to an entirely distinct genus from 
the Mylodon, and that Dr. Harlan himself recognised the di- 
stinction, when remains of a true Mylodon were first presented to 
him, and accordingly proposed, m ignorance of my previous de- 
termination of the genus, to call the extinct animal to which those 
remains belonged ‘ Orycterotherium missouriense? 
This species, also noticed as new in Prof. Wagner’s Report 
(p. 60), is synonymous with my Mylodon Harlani, first described 
m the ‘ Fossil Mammalia of the Voyage of the Beagle,’ 4to, part 3, 
1839, and afterwards with further details derived from examina- 
tion of the very Missouri specimens on which Harlan had founded. 
his genus ‘ Orycterotherium’ in my memoir on the Myledon ro- 
bustus (Ato, 1842). 
With regard to Harlan’s dAulaxodon or Pleurodon, that genus 
is much more closely allied to Megalonyz, if it be really distinct 
from Cuvier’s genus. 
And now a word for Mylodon as a name, admitting the genus 
to be a reality in nature. ‘It is true that wwAn, mola, ddovs, dens, 
implies merely a beast having molar teeth only, and no canines 
or incisors; and that this character is equally applicable to other 
genera of Megatherioids. But the same objection might be urged 
against Megalonyx (wéyas, magnus, dvuE, unguis), the species of 
which genus had not longer or larger claws than those of My- 
lodon or Megatherium. All the Megatherioids were remarkable 
for the enormous bulk and strength of their hind legs, and Sce- 
