148 PROCEEDINGS OP THE ACADEMY OP 



This species is of smaller size than the M. mustelinus, Cope,^ 

 and the sectorial tooth less elevated and trenchant. 



Cosoryx ramosus, sp. nov. 



Cha7'. Gen. Inferior molars prismatic, 3-3 ; the premolars all sectorial, 

 last with short branch crests. Molars with basal intercolumnar tuber- 

 cles. Horns superciliary, solid, branched. 



This genus was indicated by Dr. Leidj^ from a horn of the spe- 

 cies known to him, the Cosoryx fur catus^ from the Pliocene beds 

 of the Niobrara. The same, or a similar species, has left abun- 

 dant remains in the Santa Fe marls, and, in connection with the 

 more numerous G. ramosus, has enabled me to determine' the 

 dental and other characters of the genus. 



After a careful examination of the horns of these species in my 

 possession, those of eighteen individuals (at least I find that of 

 ten where the basal portion is preserved), the beam has been 

 broken off and reunited by anchylosis in six. In most of these 

 the spot is marked by a ring of exostosed tuberosities, like those 

 constituting tl\e burr of the deer's horn. The fracture has taken 

 place in every instance at a point as far above the frontal bone as 

 the burr of deer is situated, and i,s irregular in outline, higher on 

 one side than the other. In some of the specimens the smaller 

 antlers are also broken, and exhibit a similar burr, but the terminal 

 portion is usually lost. In one specimen, a broken antler is an- 

 chjdosed in the ttsual manner of overlapping ends. 



The horns are solid, the centre having a narrow spongy axis. 

 The surface is dense, and marked by arterial grooves, but not 

 pierced b^^ noticeable foramina. 



It is evidentlj^ a question whether this genus should be referred 

 to the hollow or solid horned Ruminantia, to the Bovidse or Ger- 

 vidas. The horns might be regarded as those of deer, were it not 

 for the occasional specimens without burr, while the teeth are both 

 cervine and bovine. We may here draw such inferences as we can 

 respecting the nature of the covering of the horn. That the frac- 

 tured beam should not be lost, indicates the presence of some kind 

 of covering to retain it. That this covering was not horny, is 

 probable from the fact that the horns are branched, a structure 

 impossible to the Bovidae, since antlers effectually prevent the 

 usual mode of increase of horn by additions at the base and 

 removal at the extremity. That such covering protected arteries, 



' Hayden's Annual Report, 1874. 



