78 



PERMO-CARBONIFEROUS VERTEBRATES FROM NEW MEXICO. 



vertically. Among the many pieces of spine recovered of the posterior vertebras, 

 but few of which could be connected with their vertebrae, the lateral tubercles 

 are more numerous and rather more prominent, but none could have been more 

 than three-quarters of an inch in length.* A few of the intercentra are preserved 

 with the vertebrae, one of which is figured, as seen from below. 



Large quantities of broken ribs were secured, but only one rib could be restored 

 completely or nearly completely ; it belongs with either the eighth or ninth vertebra. 

 Its shape and size will be sufficiently well understood from the figure (fig. 48 b). 

 The rib seems remarkably heavy for a skull of the size of the present one. 



Pectoral girdle: Both scapulas are preserved, imperfectly. That of the right 

 side is more complete on the lower part, that of the left on the upper. The latter 

 has a nearly complete cleithrum in close articulation with it. The right clavicle 



Fig 49 — Edaphosaurus novomexicanus. Pectoral girdle, X Vs. 

 c, cleithrum; d, clavicle; sc, scapula. 



was fotind lying across the left scapula, and is complete. No indications of an 

 interclavicle have been observed in the material. The right scapula is figured, 

 with some slight additions, as also the cleithrum, reversed from the left side (fig. 49). 

 The cleithrum is larger than has been observed in other pelycosaurs. It is a rather 

 stout cylindrical bone, lying in close articulation along the front edge of the scapula 

 above, thinned below for union with the clavicle, but not dilated at either extrem- 

 ity. The scapula is peculiar in its short, narrow, rather stout blade, and its great 

 antero-posterior extent below. Both scapulae are more or less crushed, and were 

 doubtless less fiat in life than shown in the figure. The large supraglenoid foramen 

 pierces the bone back of the ridge leading to the preglenoid facet, not the outer 

 face, as in Dimetrodon. A comparison of these scapulas with that figured and de- 

 scribed by Case f leaves little or no doubt of their generic affinity (fig. 50). Case 

 was especially struck by the short blade of his specimen, and the great antero- 



• Among the collections made by Mr. Baldwin from Poleo Creek, New Mexico, now preserved in the 

 museum of Yale University, is a considerable fragment of a large spine, closely resembling those of " Nao- 

 saurus," that has elongated lateral processes. 



t Journal of Geology for May 1903, page 397. 



