312 General Notes. [ May, 
ages. He adduced Bartram’s articles in proof of the relationship of 
these animals to the birds which he had originally pointed out from the 
structure of the feet. He also showed that they possess an extraordi- 
nary dentition, much more complex than that known to belong to the 
same class of animals heretofore described in Europe. The teeth are ar- 
ranged in vertical columns which constantly grow at the base, and which 
are kept in place by grooves in the jaw-bones. In one genus, Diclonius 
Cope, each tooth of a column overlaps the ends of those above and below 
it; while in another, Cionodon, nearly every horizontal section of the 
jaw cuts three teeth. It was estimated that there were seven hundred 
teeth in the mouth of the former genus at one time, and two thousand in 
the mouth of the latter. 
Tue Lowest MAMMALIAN Brain. — At a recent meeting of the 
American Philosophical Society, Professor Cope exhibited a cast of the 
brain cavity of a species of Coryphodon from New Mexico, and described 
its peculiarities. He stated that it is the lowest and most reptilian type 
of mammalian brain known, for the following reasons: the diameter of 
the hemispheres does not exceed that of the medulla, which is as wide as 
the cerebellum. The latter is small and flat. The middle brain is the 
largest division, much exceeding the hemispheres in size, being especially 
_ protuberant laterally. The hemispheres contract anteriorly into the very 
stout peduncles of the olfactory lobes. These continue undivided to an 
unusual length, and terminate in a large bulbus, which is at first grooved 
above, and then bifurcate at the extremity, The length of the hemi- 
spheres is one fifteenth that of the cranium, and their united bulk one 
twenty-seventh that of the hemispheres of a tapir of the same size. 
Their surface is not convoluted, and there is no trace of sylvian fissure. 
The region of the pons varolii is very wide, and exhibits a continuation 
of the anterior pyramids. The large size of the middle brain and olfac- 
tory lobes gives the brain as much the appearance of that of a lizard as 
of a mammal. ; 
Professor Cope stated that three, and perhaps four, other examples of 
this type of brain are known. The first, described by Professor Gervais, 
is that of the flesh-eater, Arctocyon, from the same lower Eocene horizon 
as the Ooryphodon. The next is that of the Uintatherium, of the Bridger 
Eocene, described by Marsh, who states that the hemispheres present 4 
sylvian fissure, in which he is most probably in error, and whose figures 
do not exhibit the convolutions which he claims to have found. e 
third is that of the Oxyena, described by Professor Cope, of which the 
middle brain is unknown, but which is probably like that of Arctocyon, 
in view of the close similarity in other respects. 
In reviewing the evidence derived from the preceding sources, the 
opinion was expressed that the type of brain shown to exist in the Am- 
blypoda and Creodonta is as distinct from that characterizing the pri- 
mary divisions of the Mammalia as they are from each other, and that 
