NATURAL SCIENCES OF PHILADELPHIA. 151 



Measitrements. m. 



Length of molar series 0050 



" of first molar 0018 



Depth below last molar (inner side) 0030 



" below first molar 0045 



" of incisor 0015 



" as diastema 0027 



Panolax sanctaefidei, gen. et sp. nov. 



Char. Gen. Molars prismatic, transverse, except the first and 

 last, each divided by a plate of enamel extending transversely from 

 the inner side. Anterior molar longitudinal; posterior molar 

 composed of two columns. 



This genus is represented by numerous teeth and portions of the 

 cranium. It evidently belonged to the Leporidse, and is allied to 

 both Lepus jind Palseolagus. As the teeth are mostly sepai'ate, it 

 is not easy to determine which is the posterior and which the ante- 

 rior molar. Judging by the analogy of the known species, the 

 determination as here made is correct; should the relations be 

 reversed the species will be referred to Palseolagus. 



Char. S2:)eci.f. The teeth are curved, the convexity inwards. 

 Inner face grooved, the groove occupied by cementum ; the outer 

 border compressed either without or with very shallow groove. 

 First molar with triturating- surface twice as Ions: as wide with 

 an entering loop of enamel on the inner side, anteriorly narrower. 

 Last molar as wide antero-posteriorly as transversely, the shaft 

 curved backwards ; the posterior column sub-cylindric half the 

 diameter of the anterior. 



Measurements. Inch. 



Diameter of middle molar i antero-posterior 



(. transverse 



first molar \ antero-posterior 

 ( transverse . 

 ( an 

 (tra 

 Length of crown of last molar 



last molar i ^ntero-posterior 

 transverse . 



.093 



.187 

 .140 

 .002 

 .100 

 .065 

 .250 



This species is about the size of the northern hare. 



Cathartes umbrosus, sp. nov. 



Represented by numerous portions of nearly all parts of the 

 skeleton, in excellent preservation. The beak from the frontal 

 bone to near the apex is preserved ; it displays the depression just 

 anterior to the nares, which marks the anterior boundary of the 



