92 



-R. S. Lull — New Tertiary Artio dactyls. 



The conclusion reached is that the horns of Aletomeryx 

 were covered permanently with hairy skin comparable 

 to those of the giraffe or the developing antlers of the 

 deer. This would be a primitive condition leading to 

 that of the prongbuck on the one hand, where the hair 

 develops into a dermal horn by agglutination, or to the 

 deer on the other, where the velvet is shed, laying bare 

 the osseous antler, which in turn is lost, There is no 

 evidence that the horns of Aletomeryx were ever shed, 

 nor that they were derived from separate centers of ossifi- 

 cation as in the giraffe; they are merely the processus 

 cornuus of the frontal bone. Their surface is not porous 

 as in Antilocapra or Bos, except on the summit, but in 

 the males is dense and polished like that of the adjacent 

 frontal bone. 



Female horns. — The relative development of male and 

 female horns in Aletomeryx corresponds to that in Anti- 

 locapra, as several skulls show. The female horn is 

 merely a low, rounded protuberance with a subtriangular 

 base. Its position is precisely as in the male, which is 

 also true of the axial direction backward and somewhat 

 outward, decidedly so in the old male. The summit of 

 the female horn is finely porous as in Antilocapra. 



The dimension of the osseous horns are as follows : 







Aletomeryx 













male 



male 







male 



male 



horn 



horn 



female 





10732 



10734 



10748 

 2 . 

 m. 



10748 

 3 

 m. 



10735 





m. 



m. 



m. 



Height above orbit 



. . -0265 



•0530 



•0365 



•0300 



■0057 



Diam. at base, ant.-post 



.. -0100 



•0135 



•0115 



•0105 



•0082 



Diam. at base, transverse . . . 



.. -0100 



•0174 



•0138 



•0137 



. -0080 



Diam. at summit,* ant.-post. 



.. -0083 



•0180 



•0188 



■0140 





Diam. at summit,* transverse 



.. -0060 



•0095 



•0090 



•0100 



rounded 

 point. 



* Somewhat oblique. 















Aletomeryx 



Antilocap 



ra 







female 





male 







female 



skull cap 



ESL 



Ost. Col. 



ESL 





10747 



10748 

 m. 



male 



1518 



female 





m. 



m. 



m. 



m. 



Height above orbit 



•0100 



•0008 



•0858t 



•0970 



•0109 



Diam. at base, ant.-post 



•0095 



•0095 



•0340 



•0373 



•0167 



Diam. at base, transverse . . . 



•0097 



•0070 



•0194 



•0225 



•0068 



Diam. at summit,* ant.-post. . 



rounded point. 









Diam. at summit,* transverse. 



rounded point. 



•0055 



point. 





"Somewhat oblique, t -1385 with dermal horn. 



