244 Bulletin American Museum of Natural History. [Vol. XIII, 



the newer characters, namely the crista and crochet, are formed 

 near the summit of the crests and are thus worn away in old 

 teeth ; while the older characters, such as the antecrochet, are at 

 the base of the crests and thus become bolder in extreme wear. 

 The same law applies to the newer and older characters in the 

 molar teeth of the horse. 



General Distinclions of Skeleton. — Skull and jaw of dolichocephalic type 

 (measurements, symphysis to condyles=63o) ; nasals long and narrow, more or 

 less separate, notched at sides, slender in females ; tetradactyl, a well developed 

 5th metapodial, lunar wedge-shaped distally ; symphysis of lower jaw varying 

 with sex, short in females, longer in males. 



These characters may be verified in the following specimens : 

 Paris, No. 2372 {Badactherium^ borbonicu?n Croizet, type, loc. 

 Auvergne), an old individual with well worn molars. Duvernoy's 

 fine type skeleton of A. gannatense (Gannat, Allier), probably a 

 female, with small lower canines and short symphysis of lower 

 jaw, large and powerful skeleton ; skull measuring 630 from 

 symphysis to condyles ; superior teeth partly worn and finely 

 preserved ; pmi-m^ = 265 ; femur measuring 460. Also A. 

 randanense, No. 2302 (Randan, Auvergne), lower jaw containing 

 pm 2-m I, with a very long symphysis (unlike the A. gannatense 

 type) ; this is possibly a sexual or male character. Also a com- 

 plete jaw (Gaillac, Tarn) with small lower canines, probably 

 female, small pm i on left side. Portion of left anterior foot. 

 No. 2373 (Gannat, Allier), showing characteristic tetradactyl- 

 ism.^ Lyons : (1) ^. lemajiense (Gannat), skull, nasals long and 

 thickened at the ends, but separate in median line, notched at 

 the sides ; this type represents an early stage, because the premolar 

 crests are bridged internally and would unite upon extreme 

 wear. (2) Large lance-shaped lower canines of lenticular sec- 

 tion, unworn (Allier). (3) Two maxillae from Gannat exhibit 

 molar and premolar characters entirely agreeing with those 

 above described. (4) A complete skull and skeleton, probably 

 female, lower jaw with small canines, medium-sized upper 

 canines, molars agree with Pomel's type in character, size below 

 that of Pomel's type ; nasals extraordinarily long, slender, extend- 



' This is possibly a MS. name. It is not recorded in Trouessart's ' Catalogus Mam- 

 malium.' 



" See Duvernoy's Memoir, Plate viii. 



