Dr. J. Murie — On the Sivatherium giganteum. 441 



The enigmatical part of the problem in the Sivatherium, palmation 

 and absence of burr, is therefore thoroughly explained in Antilocapra; 

 for the core of the Sivathere's hinder horns agrees with it, and does 

 not do so either with the antelope, deer, or giraffe. 



Knowing, as we do from the fossil specimens, that the Sivatherium 

 had four bony horn-cores, it becomes an interesting question, What 

 surmounted these, to constitute the fully-developed horns ? For of 

 the covering, whatever that may have been, no trace has as yet been 

 discovered. Of the front horns it will be readily admitted these 

 may have been similar to those of Tetracerus and other straight- 

 horned antelopes. 



The hind horns are the most difficult ones to appreciate as regards 

 their casing. One or other of the following conditions necessarily 

 existed. 



1. Each posterior horn sheath may have consisted of one deciduous 

 mass of agglutinated hairs, with corneous extremity, as obtains in 

 the living Prongbuck; or this may further have split up at the 

 forks on being cast off. 



2. The sheath may have consisted of semi-detached pieces 

 corresponding to the snags, shedding taking place by partition. 



3. The core covering might be made up of soft epidermal hairy 

 material, such as clothes the reindeer's horns, and this exfoliate, as 

 in that animal, by shreds when the periodical cessation of its growth 

 had occurred. 



4. The front horns, and probably the hinder ones also, were, like 

 those of the giraffe, covered with an investment of true skin, and 

 never cast off. 



5. Lastly, both front and rear horns might, as in the Bovidce, 

 have had firm corneous envelopes, not subject to shedding, but per- 

 sistently retained through life, save when accidentally injured. 



Analysis of the above five reasons removes a certain amount 

 of equivocation as to their nature. Admitting, for argument's sake, 

 that the covering of the front horns may have consisted entirely 

 of a horny sheath, as in buffaloes and other Bovidce, it does not 

 follow the hind ones were similarly clothed. Indeed, by force of 

 reason, from their flatness, snags, etc., it could not be so. Hence 

 necessarily follows separation from that family. 



It is quite as unlikely they resembled, nay, it may be affirmed that 

 they did not agree with, those of the modern giraffe. The median 

 fore-horn of the giraffe is epiphysial, and springs from the frontal 

 suture. The surface of the bony eminence shows impressions in- 

 dicating a skin covering. These are absent in Sivatherium. 



The hind horns of the giraffe, again, are not flat, and branched as 

 in the fossil genus compared ; and the osseous surface exhibits 

 cuticular markings. The hind horns of Sivatherium are unlike those 

 deer with flat palmate antlers clothed with a hairy membrane ; and 

 furthermore, as before mentioned, are devoid of burr; therefore 

 separate from all Cervidce. 



Lastly, then, it alone in its entirety agrees with the Prongbuck. 

 I have mentioned the possibility of each snag possessing its own 



