1891.] Remarks on Reptiles Called Dinosauria, 443 
In 1889 he keeps this arrangement and divides the suborders 
in the following families (27): 
I. Ornithopoda.—Trachodontidz, Iguanodontidz, Scelidosauridz, 
Stegosauride, Cee ; 
II. Theropoda.—Anchi gal ide, Compsognathide, 
Cceluride. 
III. Sauropoda.—Atlantosauridz, Diplodocidae, Cetiosauridz. 
In 1890 Prof. Marsh (28) separated the Hallopoda from the 
Dinosauria with query, and placed them in a special order; at 
the same time he gave the family Ceratopside, which he had 
` established in December, 1888 (Am. Journ. Sci.), the rank of a 
suborder, with the name Ceratopsia. 
After this Baur (29) expressed the opinion that Hallopus is 
nearly related to Compsognathus, and that it is unnatural to place 
the Ceratopside in a special suborder. 
In the latest paper on the subject Prof. Marsh (30) has given 
up the suborder Ceratopsia, considering the Ceratopside a 
family only. | 
Prof. Zittel (31) retains the order Dinosauria, which he divides 
in this way : 
I. Unterordnung Sauropoda. Families: 1. Cetiosauride. 2. 
Atlantosauride. 3. Morosauride. 4. Diplodocide. 
II. Unterordnung Theropoda. Families: 1. Zanclodontide. 
2. Megalosauride. 3. Ceratosauride.~ 4. Anchisauride. 5. 
Coeluride. 6. Compsognathide. 7. Hallopide. 
III. Unterordnung Orthopoda. A. Stegosauria. Families: 
I. Scelidosauridz, 2. Stegosauride. - B. Ceratopsia. C. Orni- 
thopoda. Families: 1. Camptosauridæ. 2. Iguanodontidæ, 
3- Hadrosauridæ. 4. Nanosauridæ. 5. Ornithomimidæ. 
After this review of the general classification of Dinosaurs 
we see that there are quite a number of different ideas. Leaving 
the older views aside, we have to-day the following principal 
Opinions, taking the latest views of the different authors. 
A. The Dinosauria are a Natural Group—1. -~ Dinosauria 
form a subclass of reptiles, containing four orders : 
2. Stegosauria. 3. Ornithopoda. 4. Theropoda (Marsh, 
