4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 60 



nochcetes in its long nasal bones, and' elongate rostral part of the 

 skull, in its premaxillge with rounded border, and the broad ascend- 

 ing nasal processes. The direction of the horns is outward and not 

 forward and upward over the eyes as in Connochcetes. The thoracic 

 vertebras are one less than in Connochcetes, which is unique among 

 African antelopes in the possession of fourteen. Both genera have 

 as a rule only two lower premolars in the permanent dentition, the 

 first milk molar not being replaced by a premolar. Among the species 

 of Bubalis one species, lichtensteini, stands out from the others as a 

 very different form, and shows a considerable degree of distinctness 

 both in horn shape and skull characters. The broad horn pedicle 1 

 gives the posterior portion of the skull a striking resemblance to 

 that of Gorgon. It is here considered as the type of a separate 

 genus. 



SIGMOCEROS, new genus 



Type ; Bubalis lichtensteini Peters. 



Characters. — Horns with a peculiar S- or Z-shaped curvature, 

 broad and depressed at the base, and sharply turned backward at the 

 tips ; median frontal suture raised into a prominent ridge in the 

 interorbital region ; horn pedicle a wide and short, its bifurcation 

 occurring directly above the posterior margin of the condyles, the 

 width of the pedicle equalling the distance from the bifurcation to 

 the posterior border of the orbital rim. 



In the closely allied genus Bubalis the horn pedicle is very long 

 and narrow, the bifurcation taking place well posteriorly to the 

 condyles, and the width of the pedicle is always much less than its 

 length from the bifurcation to the orbital rim. The frontal region , 

 differs further in being flat and the horns at the base are circular 

 without any marked depression as in Sigmoccros. 



The geographical distribution of this distinct type is peculiar. It 

 occupies the territory between two species of typical Bubalis with 

 neither of which it is at all closely allied. Its range extends from 

 central German East Africa southward through Nyasaland and 

 Portuguese East Africa to the vicinity of Delagoa Bay. 



The Caama, a typical Bubalis of the extreme dolichocephalic 

 lelwel type, extends northwards from the Cape region as far as the 

 Limpopo River, but does not reach the southern limits of the range 

 of Sigmoceros. In central German East Africa, Sigmoccros reaches 



1 The term " horn pedicle " is used here and elsewhere in this paper to 

 designate the posterior upper portion of the cranium, from the orbits to the 

 vertex. 



