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, whicli 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, 

 being reproduced in 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 Aulaxodon or Pleurodon 

 for Mylodon -/^ adding, " the latter of these two is evidently better 

 than Mylodon, which signifies nothing else than grinder. ^^ I 

 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 1 843) of their 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, in 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 

 in 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 Mylodon ro- 

 bustus (4to, 1842). 



With regard to Harlan's Aulaxodon or Pleurodon, that genus 

 is much more closely allied to Megalonyx, 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 ^vKt], mola, ohov^, 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 {fiiya^, magnus, ovv^, 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 See- 



