The Artiodactyla. 125 
stage of the essential character 
of the horns of the Bovidse. 
Perhaps the retention of the 
primitive dermal character of 
this investment, instead of its 
metamorphosis in to horn, might 
be regarded as a basis for a dis- 
tinct family, the Cosorycidae. 
But it is highly improbable that 
this covering remained in Siva- 
therium and Bramatherium, 
whose horns were apparently 
perfectly naked. It is not evi- 
dent how all these animals can 
be retained as distinct from the 
Bovidse, and I therefore place 
them in two subfamilies of 
that family. The Cosorycina;, 
tenoV'^' ^^' f 'b''^'^'^'^^""'-^''^"^^"''' ^°^" ^^^^^^^ ^^'^^ include Cosoryx 
size. Miocene, Fraiice"^Fr"om Gaudr'^^. and Blastomeryx, are charac- 
terized by the sheath of the 
horns being dermal ; the Sivatheriinae by the absence of any 
sheath whatever. The synopsis of genera will then be as 
follows : 
•Molars brachyodont Falaomeryx^ Von Mey. 
n. Horns covered with skin (CosorycinK). 
Teeth 
Teeth 
achyodont ; no frontal excrescence Blastomeryx Cope. 
leeth brachyodont ; two pairs of horns, all separate Sivathermm Cautl. 
Teeth brachyodont ; two pairs of horns ; those of the anterior pair from a con 
Teeth brachyodont ; one pair of horns', from distinct bases Dicroccrus ] 
IV. Horns covered with a horny sheath ; teeth hypsodont (Bovin?e). 
Horn-sheath f 
ngues. (Nasal bones normal; postzygapophyse: 
•Should T. eminens,i^^r^ of PaLxoir 
IZt^' generic_ name must ta 
