$70 The American Naturalist. [June, 
3. ‘‘ The calcaneum is compressed transversely, and much produced 
backward. It. . . strongly resembles the corresponding bone in 
There is no definite proof that the bone called ‘‘ calcaneum ” repre- 
sents this element, or that the first digit of the hind-limb was entirely 
“wanting. 
Hallopus is a true carnivorous Dinosaur, near to Compsognathus, 
there can be little doubt. This opinion was expressed already by 
Prof. Williston in 1878, in a paper published in a Journal of the 
Kansas Academy of Science, the title of which I cannot give at this 
moment. : 
In the following paper a new order of Dinosaurs, ‘* Ceratopsia,” is 
created. Ceratops Marsh, 1889, is the same as Monoclonius Cope, 
1876. This I can state with absolute certainty, having examined the 
types of Ceratops and Monoclonius. Neither ‘‘ Ceratopside’’ nor 
. “í Ceratopsia °’ can be adopted on this reason. The so-called ‘‘ Cera- 
topsia’’ are characterized by Professor Marsh in the following way : 
“(1), The skull surmounted by massive horn-cores ; (2), a rostral 
bone forming a sharp, cutting beak; (3), the teeth with two distinct 
roots; (4), The anterior cervical vertebra codssified with each other ; 
(5), the pubis projecting in front, and no post-pubis.”’ 
To this I have to make the following remarks : 
1. The skull of Phrynosoma is surmounted by stout horn-cores, 
but nobody will place it on that account in a separate order. On the 
_ Same reason the horned members of the Cervide could be placed in a ` 
different order from the hornless forms. 
2. Some of the pigs and edentates have a peculiar bone in front of 
_ the nose, not present in other mammals, but nobody places these forms 
in a separate order on this account. 
3- If the teeth would really have two distinct true roots, as Prof. 
Marsh states, this perhaps would be of ordinal character, but I do 
not believe it. These “two roots’? are probably produced by splitting 
of the tooth by the young one following. 
4. In Buceros among birds, also in some of the Plesiosauria and 
Ichthyosauria, the first two vertebre are firmly codssified ; are they 
placed in separate orders therefore ? 
5- “The pubis projecting in front, and no post-pubis.’’ Every- 
body knows to-day that what is called by Prof. Marsh the pubis is the 
pectineal process, and that his post-pubis is the true pubis. The state- 
ment that there is no post-pubis 1 do not believe before it has been 
demonstrated that the bone called pubis by Prof. Marsh and repre- 
