884 THE WHITE EIVER FAUNA. 



plane, and the enamel is marked by numerous approximated, faint trans- 

 verse undulations in well preserved specimens. 



Measurements. 



No. 1. 



u. 



Length of superior molar series 016O 



Length of seoond molar 0025 



Width of secoud molar 0043 



Length of fourth molar 003O 



Width of fourth molar 00r>5 



No. 2. 



Length of molars 0.016 



Length of three median molars 010 



Depth of ramus at central molars Oil 



Width of central tooth 0035 



No. 3. 

 Depth of ramus at penultimate molar 0130 



The deciduous molars present much the same character as in P. haydeni, 

 except that there is scarcely a trace of the odd j^osterior tubercle on the 

 second. The posterior root of the latter extends to the bottom of the 

 alveolus. The grooves of crown do not descend to the alveolus on either 

 side. Measurements of such a specimen are — 



Meas^irements. 



M. 



Length of two anterior molars 0.0068 



Length of tirst molar 0032 



Width of first molar 0021 



Depth of ramus at first molar 0085 



Depth of ramus at diastema 0061 



I have of this species portions of humeri, femora, tibiae, and astragalus. 

 They resemble very much the corresponding elements of the P. haydeni, 

 but differ strikingly in the much larger size. 



The distal extremity of the humerus has a greater transverse extent than 

 that of the P. haydeni, chiefly because of the greater size of the internal 

 epicondjde. The external trochlea of the condyles extends also a little fur- 

 ther outwards beyond the external posterior trochlear flange. The corre- 

 sponding internal flange is not nearly so prominent as in P. haydeni. The 

 olecranar fossa is scarcely perforate ; the coronoid fossa is shallow. The 

 external marginal acute edge is prolonged well upwards. The proximal 

 portion of the femur has the characters of that of P. haydeni, but the third 



