344: E. L. Troxell — Palcdolagus, mi Extinct Hare. 



additional tubercles, the bending down of the face, and the 

 nature of the air passage, all contribute to a cursorial 

 adaptation. 



Palceolagus turgidus Cope. 



Figs. 4-8. 



The largest species of Oligocene rabbit is represented 

 in the collection by several specimens consisting mostly 

 of parts of mandibular rami. One specimen, the right 

 maxillary (fig. 4), contains the complete tooth series 

 save P^. Except for the very large size, the most striking 

 thing about this species is probably the great width of the 



Fig. 5. Fig. 6. 



Fig. 5. — Palceolagus turgidus. Cat. No. 12069, Y. P. M. Crown view of 

 lower teeth. X 2. 



Fig. 6. — Palceolagus turgidus. Cat. No. 12068, Y. P. M. Crown view of 

 lower teeth, M^ lacking. X 2. 



enamel bands, covering all sides of the upper molars but 

 the outer ones. Compared to most specimens of P. hay- 

 deni, they are much wider relatively as well as actually. 



In this particular specimen the enamel pattern is simple 

 and it is evident that the teeth are much worn. They are 

 short compared to what they must have been originally ; 

 the interior folds are entirely obliterated, and they have 

 lost almost all trace of the crescents. 



Fig. 7. Fig. 8. 



Fig. 7.— Palceolagus sp. ? cf. P. turgidus. Cat. No. 12073, Y. P. M. 

 Crown view of lower molars of young individual. X 2. 



Fig. 8.— Palceolagus sp.? cf. P. turgidus. Cat. No. 12066, Y. P. M. 

 Lower teeth of young individual. X 2. 



In the mandible the enamel is continuous around the 

 teeth, but in the late stages of wear it may disappear on 

 the inner side. The incisor root has its beginning below 

 Ml, as shown by the inflated region near the ventral 

 border of the ramus. 



The specimen shown in figure 5, a lower jaw, corre- 



