126 THE PERMO-CARBONIFEROUS RED BEDS OF 



such weak-shelled or soft-bodied invertebrates, crustaceans, worms, insect 

 larvae, etc., as it might discover, and it probably did not refuse carrion, or 

 even vegetable matter of some kinds. 



It has been suggested that the great projecting horns may have sheltered 

 external gills, but of this we have no knowledge. Perhaps the animal rose 

 to the surface at long intervals for air, or pushed its nose beyond the edge of 

 the water along the bank. Mr. Paul Miller has noted the fact that the bones 

 of Diplocaulus are almost always associated with the teeth of sharks, which 

 may be taken as confirmatory of the fresh-water habits of ancient sharks, 

 and perhaps as an indication of a favorite food. 



A tracing of a nearly complete specimen furnished the author by Mr. 

 Doughtett measures approximately 950 mm. This would be a good-sized 

 individual of Diplocaulus magnicornis. 



Eryops (plate 20, fig. 2) . — ^The skeleton of the genus, typically represented 

 by Eryops megacephalus, is as completely known as any form from the Permo- 

 Carboniferous Red Beds. It was the largest of the amphibians, reaching a 

 length of 6 feet or more. If, as restored in the American Museum of Natural 

 History in New York, it had a long tail, the length may have been even 

 greater. Dr. Matthew assures me that the long tail is warranted by speci- 

 mens which I did not see when working upon the collections in the American 

 Musetim. Neither Dr. Williston, Mr. Paul Miller, nor myself, all of whom 

 have collected several times in the Texas beds, has seen any evidences of 

 such a long tail, and I have collected two specimens in which the nearly perfect 

 vertebral column indicated that the tail was decidedly short, as I have restored 

 it. (Carnegie Inst. Wash. Pub. 145, plate 9.) It is also to be noted that in the 

 original figure of the vertebral column given by Cope ^ the vertebrae, which 

 he speaks of as having coossified chevrons and near the extremity of the tail, 

 are still of good size, indicating that there was a rapid decrease in the size of 

 the caudal vertebrae and a short tail, if his observation of the position of 

 these vertebras is correct. The bifurcated distal ends of the neural spines of 

 the anterior caudal vertebrae afford some support to the idea of a long tail, 

 as they would have given attachment to powerful muscles and tendons. 



Long-tailed or short-tailed, Eryops was a heavy-bodied Stegocephalian, 

 with a large head and relatively short limbs. The bones of the limbs show 

 the attachment of powerful muscles, and the carpal and tarsal bones were 

 well formed and closely articulated. The clavicles and interclavicles were 

 relatively small and the pelvis was a solid mass of coossified elements. The 

 foot, as indicated by the phalanges, was short and strong. Altogether the 

 skeleton gives the idea of an animal with considerable ambulatory powers, 

 able to raise the body well off the ground in progression ; a totally different 

 creature from the weak-limbed Triassic Metopias, with its great pectoral 

 shield formed of the clavicles and interclavicle, which protected the thorax 



° Cope, Proc. Amer. Phil. Soc, vol. xix, pi. iii, 1880. 



