144 



THE PERMO-CARBONIFEROUS RED BEDS OP 



height to a few centimeters, and lie beneath the spines of the sacral and 

 posterior lumbar vertebras, which curved abruptly backward. The length of 

 the tail is unknown, but it was probably fairly long. The genus was rich in 

 individuals and several species have been identified. The remains are not 

 uncommon, but almost always consist of the fragments of spines, or complete 

 isolated spines. This condition of the remains has been regarded as indi- 

 cating that the animal's habitat was rather far from any place where the 

 body could be easily embedded, and that it was disintegrated by carrion 

 feeders, decay, or transportation for some distance, before burial. 



Edaphosaurus was a slow-moving, harmless creature, feeding upon small 

 invertebrates of all sorts and possibly vegetation. The powerful claws, if 

 they belonged to this animal, would have been useful in digging in the soft 

 earth or vegetation, or in tearing open decayed stumps and logs in search of 

 insects, etc. If, as suggested, its habits confined it more to the upland, away 

 from the waters and the abundant vegetation, it was perhaps beyond the 

 ordinary range of the fierce carnivorous forms, and so found the peace and 

 full nourishment which permitted the development of the enormous spines 

 as a physiological excess. 



The largest known specimens would have a length of about 2 meters, if 

 we assume that the tail was as long as the rest of the body. 



The single imperfect skeleton discovered in New Mexico, and described 

 as Edaphosaurus novomexicanus, is, so far as it is known, very similar to those 

 recovered from Texas. The imperfect skull shows the same form and the same 

 arrangement of the teeth. The dorsal spines are more slender, with fewer and 

 less well developed tubercules. Of the appendicular skeleton little is known. 

 The conformation of the cervical vertebras , as suggested by Williston , would per- 

 mit the head to be thrown far down and even bent under the body, an attitude 

 which would bring the anterior spines forward. If this is correct, it is the 

 first hint of a use, defensive or otherwise, which has been found for the spines. 



The single small fragment described as Edaphosaurus (Naosaurus) ray- 

 mondi, from near Pittsbtirgh, is far too uncertain to use as a basis of any 

 conclusion. It is not improbable, however, that Edaphosaurus ranged over 

 the eastern United States, if, as supposed, it was an upland animal, and as 

 its remains have been found in eastern Europe. 



Platyhistrix. — In New Mexico there are found the remains of another 

 long-spined creature, as yet but little known. The spines are shorter than 

 those of Edaphosaurus, but are very large for the size of the vertebrae and 

 very rugose upon the sides. The shape, size, and character of the skull and 

 teeth are all unknown. We have here but a glimpse of another long-spined 

 form which remains to be worked out. 



Caseasauria. 



Casea (fig. 30). — The head of this remarkable creature, as described and 

 figured by Williston, was short and broad, with a flat or even slightly con- 



