

1890.] Scientific News. 301 
-by Prof. Cope and Mr. Lydekker, of the British Museum. Among 
other cases of the kind, I may mention only two, of one of which Dr. 
O. Meyer has already written. In 1877 Prof. Marsh described a new 
mammal under the name of Apatodon mirus, from the Jurassic of the 
Rocky Mountains, with the following words: ‘‘ One of the most 
interesting specimens hitherto found in the Rocky Mountain region, is 
a portion of a lower jaw with the last molar in place. This fossil is 
widely different from anything yet discribed, and its exact affinities 
are doubtful. The fragment pertained to an animal about as large as 
_a Tapir, and the general appearance of the specimen at once suggests 
the mammalian type. The tooth most resembles, in form and superior 
surface of crown, that of a typical suilline. The structure of the 
tooth, however, is different, and: the fangs are, in part at least, coössi- 
fied with the jaw. 
‘ This specimen was found near a locality where Dinosaur bones 
were abundant, and it is possible it may belong with that gronp. The 
jaw, however, is very unlike any corresponding jaw of a Dinosaur, so 
far as now known, The geological horizon is Lower Cretaceous or 
Jurassic.’’ ‘ ; 
This was certainly a most interesting discovery. A mammal as big as 
a Tapir, from a Jurassic or Cretaceous formation, from which only very 
small Marsupial-like mammals were known, a mammal with teeth like 
a typical suilline from such an old formation, a mammal with the 
teeth partially coossified with the jaws, is something startling new! I 
had the greatest curiosity to see this specimen, and fortunately my cu- 
riosity was gratified. The hog-jaw from the Cretaceous or Jurassic 
was a weathered piece of a Dinosaurian vertebra, from the neural 
spine, somesparts of which looked something like a tooth of a hog. 
Prof. Marsh knew of this mistake long ago, but he has not found it 
necessary to correct it. Only in his list of genera printed for private 
use, this specimen appears as a genus of Dinosaurs. 
Another example. In 1884 the palæontological world was aroused 
by the highly important discovery by: Prof. Marsh of a Dinosaur 
which was said to have the metatarsals united, just as a bird. The- 
metatarsus of this reptile, called Ceratosaurus by Prof. Marsh, was 
figured side by side with the corresponding bone of a penguin, and at 
the end of the paper the following sentence occurs: ‘‘ All known 
adult birds, living and extinct, with possibly the single exception of 
archeopterx, have the tarsal bones firmly united, while all the Dino- 
. sauria, except Ceratosaurus have these bones separable. This excep- 
tion in each case brings the two classes near together at this point, and 
