PERMO-CARBONIFEROUS VERTEBRATES FROM NEW MEXICO. 79 



posterior extent below, characters unlike those of other scapulas that have been 

 observed from Texas. It undoubtedly belongs with some one of the species of 

 Edaphosaurus described from Texas. 



Humerus, radius: The humerus and radius of the right side, found lying closely 

 related to the scapula, are so poorly preserved that only their chief characters can 

 be made out. The humerus is more slender than usual ; the entepicondylar foramen 

 appears to be larger. It measures 130 mm. in length, with the least diameter of 

 the shaft 14 mm. The radius is 80 mm. in length, or less than two-thirds the length 

 of the humerus. In Dimetrodon the radius is more than four-fifths the length of 

 the humerus. 



Fig. 50. — Edaphosaurus sp. Scapula-coracoid of a specimen found 

 on Coffee Creek, Texas. No. i86, University of Cliicago, X K. 



CONCLUSIONS. 



It will be observed that the cervical spines of the present species differ mate- 

 rially from those figured and described as belonging with "Naosaurus," in their 

 greater anterior inclination, more slender and pointed shapes, and in the smaller 

 development of lateral tubercles so characteristic of the genus. It is quite possible 

 that these differences are of generic value, and that Naosaurus will eventually be 

 found to be a valid genus. But this can not be determined until the type species of 

 Edaphosaurus has been definitely correlated with its proper skeleton. It is more 

 probable that the New Mexico species will prove to be the aberrant form, requiring 

 a new generic name. If these differences really exist in the Texas species, it will be 

 quite time enough to validate the name Naosaurus when the facts shall have been 

 determined. For the present, at least, Naosaurus has no claims for existence. 



In E. novomexicanus, with the neck extended horizontally, the pointed spines 

 of the anterior vertebrae would project over the occiput. If the neck were fully 



