SCIENTIFIC SUMMARY. 
327 
It proves conclusively that the brain was proportionately smaller than in 
any other known mammal, recent or fossil, and even less than in some 
reptiles. It was, in fact, the most reptilian brain in any known mammal. 
In D. mirabile the entire brain was actually so diminutive that it could 
apparently have been drawn through the neural canal of all the presacral 
vertebrae, certainly through the cervicals and lumbars.” 
Remains of Coryphodon and Dinocerata. — The examination of a series of 
Mammalian remains, obtained from the Eocene deposits of Wyoming, 
Utah, and New Mexico, has led Professor Marsh to infer that the genus 
Bathmodon described by Professor Cope clearly belongs to the genus 
Coryphodon of Owen. This is especially important and interesting, as the 
geological horizon of the remains is essentially the same in both countries, 
and the American specimens promise to clear up many doubtful points in 
regard to the animals themselves. The characters shown in the skull and 
limbs of Coryphodon indicate that this genus was essentially Perissodac- 
tyle, and represents a distinct family which may be called Coryphodontidm. 
Professor Marsh has described the principal characters of a well-marked 
group of gigantic mammals, which are abundant in the lower Miocene de- 
posits on the eastern slope of the Rocky Mountains. These animals, the 
Brontotheridse, of which four genera are known, equalled in size the gigantic 
Eocene Dinocerata, and resembled them in some important features, but 
differed from them in having but a single pair of horn cores and no crest 
around the vertex ; the structure and number of the teeth were also quite 
different, and do not belong to the same order, but constitute a distinct 
family of Perissodactyles. 
Birds icith Teeth. — The same author has also given an account of a 
remarkable group of birds with teeth, obtained from the cretaceous beds 
of Kansas, where the associated vertebrate fossils are mainly Mososauroid 
reptiles and Pterodactyls. They constitute a sub-class, Odontornithes, com- 
prising two orders — the Ichthyornithes , having the teeth in sockets, bi- 
concave vertebrae, a keeled sternum, and wings well developed, represented 
by Ichthyornis and probably Apatornis, and the Odontolcce , with the teeth 
in grooves, the vertebrae as in recent birds, a sternum without keel and 
rudimentary wings, represented by Hespeornis. The occurrence of toothed 
birds in England has been described by Professor Owen from the London 
clay of Sheppy. 
American Fossil Fishes. — Professor J. S. Newberry has further described 
the structure and relations of Dinichthys and other fossil fishes from the 
Devonian and Carboniferous strata of Ohio. The most striking feature of 
Dinichthys, apart from its great size, is the dentition, which is massive and 
peculiar, and offers some remarkable and suggestive points of resemblance 
with Ooccosteus among fossil, and Lepidosiren among living fishes, besides 
which there is a singular correspondence between the ventral shields of 
Dinichthys and Coccosteus. From the examination of a large amount of 
new material, Professor Newberry remarks that the discovery of Dinichthys 
is a matter of interest, not simply because it adds another and the most 
gigantic to a strange extinct group of fishes, but also because it serves 
as a connecting link between several genera of Devonian Placoderms, of 
which the affinities have been somewhat obscure, viz. Coccosteus and 
