Mastodontoid and Megatherioid Animais. 561 
from amid the alluvia of a tributary of the St. Louis river, where 
the chief remains had probably been an object of superstitious tra- 
dition on the part of the Indian tribes. It does not appear 
whether the zealous Prussian had any scruples to overcome ; 
but I presume they must have been considerable, if I were to 
judge from my own experience in other wild countries. In tra- 
velling along the eastern flanks of the Ural Mountains, it was my lot 
to visit many sites of gold alluvia in which bones of the mammoth 
and other extinct quadrupeds are found, and for these remains the 
poor Bashkirs, the original inhabitants of the tract, preserved so 
deep a veneration, that in freely permitting the search after the 
true wealth of their country which they were incapable of extract- 
ing, their sole appeal to the Russian miners was, “ Take from us 
our gold, but for God’s sake leave us our ancestors.” 
Overcoming, however, all difficulties, M. Koch succeeded in ex 
tracting, and afterwards in setting up, the most complete specimen 
of the species which has ever been seen. Applying to it the provi- 
sional name of “ Missourium,” he exhibited it for some time in the 
United States, and then brought it with many of the associated bones 
to London, in the hopes both of having the remains perfectly described 
and of obtaining for them a price worthy of the British nation. 
The arrival of such a collection could not fail to excite the most 
lively interest and curiosity among our naturalists, and the bones 
having been attentively examined by many members of this Society, 
produced a diversity of opinion respecting the generic character 
of the chief remains. North America had long been a fertile 
mine of such reliquiz, and the naturalists of the United States 
had not been backward in studying and describing them. It is not, 
therefore, a little remarkable that the same difference of opinion as 
to the generic and specific identity of the animals that prevailed 
across the Atlantic, is presented in the Memoirs which have recently 
been read before us; Dr. Harlan and Mr. Cooper having main- 
tained opinions, with which, to a great extent, Professor Owen con- 
curs, whilst Dr. Grant and M. Koch have supported the views of the 
late Dr. Godman. 
Citing the American authorities on his side of the question, in- 
cluding Dr. Hayes, and enumerating no less than thirteen species of 
Mastodon and six species of Tetracaulodon, Dr. Grant has made a 
vigorous effort to vindicate the true generic characters of the Te- 
tracaulodon as founded on the presence ofa tusk or tusks in the 
lower jaw and certain variations in the form of the crowns of the 
molar teeth. 
This view has been sustained by Mr. A. Nasmyth in an elaborate 
paper “On the Minute Structure of the tusks of extinct Masto- 
dontoid animals.” Microscopical examination of portions of the tusks 
believed to belong to five distinct species, viz. Mastodon giganteus, 
Tetracaulodon Godmani, T. Kochii, IT. Tapiroides and the Mis- 
sourtum, has also led this author to the same inference as Dr, 
Grant ; and he concludes with the remark, that, if it be established 
that specific differences positively do exist among all these animals, 
