ox SOME GTBBOXS RECENTLV LIVIXG IN THE GARDENS. 353 



form of the head and the character of the tail it is distinctly 

 Kudu-like. 



In conclusion, I may reiterate my opinion that Tragelaphus 

 huwtonl tends to connect the Bushbuck gi'oup so closely with the 

 Kudus as to render the generic separation of the latter from 

 Tragelaphus (in which, as already stated. I include Limnotragus 

 as a subgenus) inadvisable. 



EXPLANATION OF PLATE XVI. 



The tj'pe specimen, a subadult buck, of the Mountain Nyala, 

 Tragelaphus buxtoni. 



18. Observations on different Gibbons of the Genus 

 Ht/lob ate snow or recently living in the Society's Gardens, 

 and. on Symplialangus si/ndadylus, with Notes on Skins 

 in the Natural History Museum, S. Kensington, By 

 Dr. F. D. Welch, F.Z.S. 



[Received November 29, 1910: Read February 21, 1911.] 



Very few specimens of the genus Ift/I abates arrive in good health 

 in England or live for more than a few months, but during the 

 last five years the Society has exhibited examples of dijSerent 

 species, of which the following are now living in the Gardens : — 

 A male of the rare H. hainanus from Hainan, which arrived in 

 December, 1907 ; a male H. leuciscus from Borneo, which arrived 

 in May 1908 ; and a female H. agilis from Sumatra, which arrived 

 in December 1905. In addition to these an adult male 

 Symphalangus syndactylus in good health arrived on October 26, 

 1910, and is the finest specimen the Society has yet received. 

 As some external characters and the coloration and voice can be 

 studied only in living specimens, some observations I have made 

 on these genera may be worth recording. 



In the genus Hylohates, from observations taken at intervals on 

 four males living in the Gardens, I am strongly of the opinion 

 that the development of certain parts of the extei-nal genital 

 organs is delayed to a later period of life than is the case in 

 Authropopithecus and Man, and, so far as I can discover, no notes 

 have been published on this subject. My attention was first 

 drawn to the subject by Mansbridge, keeper of the Society's Apes, 

 but I have not accepted any information from him until I have 

 confirmed it myself, and I am well aware that several mistakes 

 have previously been made about the sex of Hylohates on account 

 of the large clitoris being mistaken for the penis (see Pocock, 

 P. Z. S. 1905, vol. ii. p. 169). I have made a careful examination 

 of ail the specimens, and am certain that the sex is as I have 

 stated. 



The male E. hainanus has altered greatly in the external 



