522 SIR VICTOR BROOKE ON HYDROPOTES INERMIS. [Mar. 19, 



6. On Hydropotes inermis and its Cranial Characters, as 

 compared with those of Moschus moschiferus. By Sir 

 Victor Brooke, Bart., F.Z.S. 



[Eeceived March 14, 1872.] 



Having received from Mr. Gerrard three perfect skulls of the rare 

 ruminant Hydropotes inermis, lately described by Mr. Swinhoe, I 

 have thought it worth while to lay before the Society a few observa- 

 tions on its dentition and cranial characters, supplementary to those 

 afforded by the describer in the Society's 'Proceedings' for 1870, 

 p. 89. In addition to my own specimens, which consist of an adult 

 male and an immature male and female, I have had the advantage of 

 examining the skull of a remarkably fine old male, presented a short 

 time ago to the College of Surgeons by Dr. Hamilton, and noticed 

 bv him at the meeting of this Society on the 5th of December last*. 

 I have also seen Mr. Swinhoe's type specimens. I fear, however, I 

 must differ from Mr. Swinhoe in so far as he considers that this species 

 evinces affinity in its cranial characters to the Cervus pudu of Chili. 

 In the general form of skull, as well as in the details of cranial 

 structure, Cervus pudu appears to me to differ considerably from 

 Hydropotes inermis, and to exhibit close affinity to the simple horned 

 Brocket-deer of South America, included in the subgenus Coassus. 

 In this form the suborbital fossa is remarkably shallow — in one 

 species, Coassus rufus, almost absent. To Moschus the affinity of 

 Hydropotes, as far as general cranial characters are concerned, is 

 more decided ; there is the same remarkable narrowness and 

 elongation of skull, the total suppression of horns, and vigorous 

 development of canines in the males. But notwithstanding these 

 more superficial resemblances, an examination of the base of the 

 skull reveals distinctive characters, which I think fully warrant the 

 generic rank Mr. Swinhoe has assigned to the species. The form 

 and structures surrounding the auditory bulla differ widely in Hy- 

 dropotes and Moschus ; and the consideration of the important 

 results arrived at by Professor Flower in his classification of the 

 Carnivora in the 'Proceedings' of the Society for 1869, p. 4, along 

 with the recollection of Mr. Turner's natural arrangement of the 

 Bovidce in the 'Proceedings' for 1850, p. 164, both of which 

 sound classifications are founded on characters derived from this 

 part of the cranium so widely removed from the modifying power 

 of adaptation, induce me to attach the highest taxonomic value to 

 such characters. In Hydropotes the auditory bulla is large and 

 much inflated, having a deep depression on its external surface for 

 the reception of the tympauo-hyal ; the external auditory meatus 

 opens immediately into the bulla, there being no spout-like prolon- 

 gation of the tympanic bone. In Moschus the auditory bulla is 

 remarkably small, the petrous portion of the periotic being visible, 

 when viewing the base of the skull, for nearly the entire length of 

 * See P. Z. S. 1871, p. 702. 



