CEEODONTA. 287 



diapophyses unless a small, narrow, broken area indicates the base of a very 

 rudimental one This is at the anterior end of a strong- longitudinal ridge, 

 which marks the inferior part of the side of the centrum The anapophy- 

 ses* are strong, inclosing the anterior zygapophyses of the succeeding 

 vertebra on the lower side. In Ursus ardos, Canis familiaris, and Felis catus 

 there is no vertebra intervening between the last bearing a rib and the first 

 bearing a diapophysis. In Ursus ardos, the centra are short, and the dia- 

 pophysis occupies an elevated position. In Stypolophus viverrinus, the cen- 

 trum is moderately elongate, and the ridge representing the diapophysis 

 has an inferior position, resembling rather Canis and Felis in these particu- 

 lai's. A portion of the sacrum preserved shows it to have been of robust 

 proportions. Besides the superior intervertebral foramina, there is a small 

 one each side of the neural arch in front of the posterior zygapophysial 

 ridge. A caudal vertebra is relatively large in all its dimensions. A frag- 

 ment of the femur shows that both the great and little trochanters are well 

 developed, the former inclosing the usual fossa. The distal halves of both 

 tibise are preserved, one of them adhering to a mass of the vertebrae. The 

 shaft below the middle is subcylindric, while the distal end presents the 

 peculiarity common to all the flesh-eaters of the Wasatch Eocene epoch. 

 The astragalar surface is without groove, and is oblique, both transversely 

 and longitudinally. The inner extremity of the bone is produced down- 

 wards, fitting the inner oblique face of the astragalus, as well as the con- 

 cavity of the side of the neck by its end. There are no strong ligamentous 

 grooves. The bones of the feet are unknown. A comparison of such por- 

 tions of the limb bones as I have observed (those of S. viverrinus) with 

 those of Felis catus (domesticus), Canis familiaris, and Ursus ardos, has the 

 following result: In the humerus the tuberosities are not so pronounced ; 

 especially is the great tuberosity more produced upward and outward in 

 the recent genera, whence the bicipital groove is deeper. In Ursus ardos 

 the greater tuberosity is also produced more posteriorly, and in all of the 

 species named, its posterior bounding ridge is more pronounced on the shaft 

 than in P. viverrinus. The great trochanter of the femur has the elevated 

 position of that of Felis and Canis rather than the depressed form of that 



* In my description of this genus in the Wheeler Reports, these processes were called metapophyses. 



