A NEW FORM OF DIPLOCAULUS 
M. G. MEHL 
University of Missouri 
To all who have worked with the genus Dzplocaulus, the great 
variety in the shape of the skull and the peculiarities in other 
parts of the skeleton are known. Even after the analysis of the 
group by Case, Williston, Douthitt, and others the several species 
assigned to the genus are not entirely satisfactorily defined and 
there are many details of the anatomy still to be determined. 
Recently, through the courtesy of Professor R. D. Salisbury 
and with the assistance of Mr. Paul C. Miller, the writer was 
permitted to examine the many specimens of Dzplocaulus in Walker 
Museum, the University of Chicago. Among the materials is a 
recently discovered specimen which, because of its distinctness 
from described forms and the possible light it throws on the develop- 
ment of the Diplocaulian characteristics, is worthy of description. 
Diplocaulus primigenius SP. NOV. 
The material herein described consists of a large skull of the 
type designated by Case* as D. magnicornis, nine dorsal vertebrae, 
seven ribs, and a fragment that the writer takes to be a part of 
the right clavicle. All these parts are well preserved and have 
been skilfully prepared and mounted on a plaster base by Mr. 
Miller. 5 
When found the vertebrae formed a curved, but unbroken 
series extending back from near the posterior border of the skull. 
At least one of the anterior vertebrae is missing. The ribs lay 
in an orderly pile to one side of the vertebrae. 
THE SKULL 
While the skull is essentially complete, its state of preservation 
prevents a detailed description of its characteristics. Little or 
tE. C. Case, ‘Revision of the Amphibia and Pisces of the Permian of North 
America,” Carnegie Inst. of Washington, Publication No. 146, (1911), p.21. 
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