142 Notice of two New Fossil Mammals. 
laqueatus, Mylodon Darwinii, and to which might be now also 
added Orycterotherium Missouriensis.. In fine, Pleurodon would 
characterize a group of genera, but Mylodon affords no character 
whatever. 
Prof. Owen has recently read a memoir before the Geological 
Society of London, on the fossil bones contained in Mr. Kock’s 
collection now exhibiting in London, and during last autumn in 
Philadelphia. Mr. O. after a minute examination of the numer- 
ous portions of the mastodons in this collection, of every age and 
size and of both sexes, many with the tusks of the inferior jaw 
in various stages of development ; and on the-existence of which 
the late Dr. Godman attempted to construct a new genus under 
the name of “ T'’etracaulodon”—arrives at the conclusion, that 
all these mastodon crania belong to one species, and that the ge- 
nus “Tetracaulodon” is without foundation. A conclusion at 
which we arrived immediately, so soon as the name was pub- 
lished ; our opinion was made public at the time, and again re- 
published in the Medical and Physical Researches, p.257. Cop- 
ies of this notice were sent to scientific persons abroad, to editors 
of journals, &c., and Mr. Owen possessed a copy. The notice 
was also republished in Jameson’s Edinburgh Journal. ‘The genus 
“ Tetracaulodon,” has long since been consigned to the “tomb 
of the Capulets.” The subject, in fine, is one upon which tio 
two naturalists could contend in opinion. — If a difference of opin- 
ion had existed, the decision of Prof. Owen, with such a mass 
of material on which to found his sudgmient; with the natura 
of Europe, will admit of no appeal. 
In the Transactions of the American Philosophical Sodtety fos 
1831, I published a notice of “Ichthyosaurian Remains discov- 
ered in the State of Missouri.” This essay was republished in 
the “Medical and Physical Researches,” 1835, p. 344. Subse- 
quently in 1839, January 9th, I read a memoir upon the. same 
subject before the London Geological Society, and proposed to 
change the name of this era to “Bi ose Missouri- 
= 
Twas aan by Professor Golafass of the Caisedeity of Bonn, 
iis Oct. 1839, a principal portion of the skeleton of a fossil ani- 
mal wis mnay: aan se papeiai ¥ Maximilian Prince 
de Wied. — 
i‘ we Th ee eet 
