VERTEBRATE REMAINS, PORT KENNEDY BONE DEPOSIT. 257 



both series the grinding face of the m^ is considerably more elongate than those of 

 the other true molars ; and the pm- 2 - is longer than any of the molars except pm- 3 - 

 and m- 3 -. 



Under the circumstances it is necessary to distinguish two races of Equus fra- 

 ternus, 1 as already indicated : E. f. fraternus, and E. f. pectinatus, which may 

 prove to be distinct species. The measurements of the superior molars of the Port 

 Kennedy specimens of the former are as follows : 



Measurements. 



mm. 



Diameters, pin 2 { anteroposterior at middle ; 29 



1 ( greatest transverse ; 28 



Diameters, pml 1 anteroposterior ; 28 



' L \ transverse ; 29 



tv ±. if anteroposterior ; 25 



Diameters, m 1 < , l no 



' ( transverse ; 28 



Diameters, m^ I anteroposterior ; 25 



I transverse; 28 



Diameters m- 3 - \ anteroposterior (grinding face) ; 32 



' ' ( transverse ; 25 



Diameters 1^ I anteroposterior ; 10 



{ transverse (oblique) ; 19 



The measurements of the teeth of the var. pectinatus are as follows : 

 Measurements. 



mm. 



TV , 9 f anteroposterior at middle ; 32 



Diameters, pm- 2 - 1 , r , , 01 



' x ( transverse, greatest ; 31 



tv , f anteroposterior; 29 



Diameters, pm- 1 - { , l 0rt 



' L \ transverse ; 32 



!-.. , ( anteroposterior; 26 



Diameters, m 1 < . D i 



\ transverse ; 31 



-rv ., I anteroposterior; 27 



Diameters, m^ < , OA 



( transverse ; 30 



t.. o ( anteroposterior; 34 



Diameters, m 1 \ , r or - 



( transverse ; 2 / 



-p.. T o (anteroposterior; 10 



Diameters, I'M , on 



( transverse ; 20 



The anterior face of the superior incisors displays a shallow groove interior to 

 the middle vertical line of the crown. 



The lower jaw above referred to, pertains to the typical form of E. fraternus. 

 The metaconid metastyle is short anteroposteriorly and is deeply grooved on its 

 internal face, the entering angle of the section of the groove being open on the 



anterior teeth, and becoming sharper posteriorly. The size of this lobe, the slight 



^ope, Proc. Am. Phil. Soc, 1895, p. 165. 

 33 JOURN. A. N. S. PHILA., VOL. XL 



