322 DR. C. J. FORSYTH MAJOR ON FOSSIL GIRAFFID^. [MaV 0, 



frontalia. It is, however, a well-known fact that in the Giraffe the 

 parietals participate also in the conformation of the horns. In the 

 skull of a very young Giraffe, such as that which is to be seen in the 

 remarkably instructive exhibition in the Hall of the British Museum, 

 it is evident that the pair of horns are not formed alone by the bi)ny 

 processes which are situated partly on the frontals and to a large 

 extent on the adjacent parietal region, but that those bones themselves 

 are thrust up, the parietals still more than the frontal>. It is not 

 possible to demonstrate with certainty the coronal suture in the cast 

 of the Hydaspitheriiim skull \ But its comparison with a young 

 Giraffe, and with the so-called skull of Ilelladotherium from the 

 Siwaliks, which is placed by Riitimeyer himself amongst the Giraf- 

 fidre -, is strongly suggestive that in all three the parietal region has 

 about the same extension and continues in the same direction as the 

 frontal region. The horns of Ili/daspitkerium, in my opinion, thus 

 occupy the same position as in the Giraffe — that is to say, on the 

 parietal as well as ou the frontal bones, only extending much more 

 forwards than in theiiving genus. 



In spite of the enormous elevation of the bones which form the 

 brain-case, this last in Hydaspitlieriuni is not much shorter than in 

 the hornless skull of the Siwaliks. 



Similarly I am inclined to believe that in Sivatlierium the parie- 

 tals also take part in the horizontal covering of the skidl, so that 

 the analogy with the Gnu and the Boviiies, advocated by Riitimeyer ^, 

 is not justified. Tbe posterior antler-like pair of horns, according 

 to my view, evidently arises from the parietals. The anterior pair 

 occupies the same position as the horns of Samotheriinn, the homo- 

 logy with which is completed by the important fact that we can 

 trace a suture between the anterior processes of Sivatherium and 

 their supporting frontals. 



The supposition as to the extension of the parietalia in >S^2ra^7ten«>M 

 and Hydaspitlierium CAXi be definitely proved only when we are al)le 

 to trace the coronal suture ; but even it Riitimeyer's improbahle view 

 as to the position of the parietalia « ere right, tliere would not be, for 

 the reasons given, sufficient grounds for uniting these fossils with 

 some of the Antelopes. 



Be that as it may, the present exposition of facts corroborates 

 Lydekker's view that Sivatherium and Hydaspitherium are nearly 

 akin to the Giraffe^. 



'^ Lydekker was unable to trace the coronal suture in tJie original. He says 

 in the description of the skull of Hydaspitlieriurn mcgaccphalnm in (juestion 

 (Indian Tertiary and Post-Tertiary Vertebrata, vol. i. 1880, p. 163): — " Above 

 the occipital crest the common base of the horn-cores rises almost vertically, 

 somewhat after the manner of the intercoronal ridge of tlie oxen. It is impos- 

 sible to say bow much of this portion of the cranium is formed by the parietals 

 and how much by the frontals, but I am inclined to think that in the middle 

 line the parietals formed a very narrow strip as in the true oxen." 



- L. c. pp. 74-78. 



^ L. Rutimeyer, ' Beitrage zu euisr natiirlichen Geschiehte der Hirsche,' i. 

 pp. 80-81. 



^ As to J'is/iMutkcrium, from tlie Siwaliks, described by Lydekker, I have no 

 new observations of my own to oiler, but I completely share Lydekker's views as 



