NO. I THE WHITE RHINOCEROS HELLER 20, 



5. P. C. — Specimens from Major Powell-Cotton's collection from localities 



in the Lado Enclave. 



6. P. M. — Paris Museum. Specimen from South Africa. A mounted 



skeleton. 



7. R. C. — Rhino Camp, Lado Enclave specimens shot either by Col. Roose- 



velt or Kermit Roosevelt, and now preserved in the United 

 States National Museum. 



8. S. A. M. — South African Museum. Skull from measurements given by 



Sclater in S. Af. Mams. I, p. 300. 



9. S. M. — Selous' Museum specimen. Collected by F. C. Selous in Southern 



Rhodesia, between Matabeleland and Mashonaland. Nasal 

 boss cut off. 



10. 2154. — Museum of the Royal College of Surgeons, London. Specimen 



shot by R. Gordon dimming in South Africa. 



11. 11.5.13.1. — British Museum. Specimen from Zululand. 



f 51. 12.23. 1. — British Museum. South Africa. No exact locality. 

 * ^52.12.9.1. — British Museum. Recorded. Figured in plates. 

 13. Type of cottoni in British Museum. Shot by Powell-Cotton in the Lado 

 Enclave. 



THE EQUATORIAL OR NILE RACE 



The square-mouthed rhinoceroses living in the Lado Enclave were 

 separated subspecifically from those of South Africa by Lydekker in 

 1908 under the name Rhinoceros simus cottoni. The material upon 

 which the describer based his conclusions consisted of three skulls 

 in the collection of the British Museum. One of these was the skull 

 of a male from the Lado, and the other two were a male and female 

 skull from South Africa. The Lado skull, which is the type of the 

 new race, was obtained by Major Powell-Cotton some distance north 

 of the station of Kiro, almost precisely on the northern boundary of 

 the Lado Enclave. It is number 53 of his collection, but has now 

 become by donation the property of the British Museum.. The differ- 

 ences detected between these skulls were a, greater width of the ter- 

 minal boss of the nasal bones and less projection beyond the maxillary 

 in the Lado skull. It was also suggested that very probably the north- 

 ern form possessed shorter horns. A study of the present series of 

 skulls from the Lado has shown the nasal boss to be subject to much 

 variation due to sex and also to some individual variation. The width 

 of the nasal expansion is always considerably greater in the male. 

 This is directly in accord with the enlarged base of the horn in this 

 sex which receives its support from the nasal boss. The projection of 

 the nasals beyond the maxillary bridge is also greater in the male, 

 but there is greater individual variation in this dimension than in the 

 width. Both of these dimensions in adults vary much, some exceed- 



