Brush-tailed Porcupine of Central Africa. 89 



fine skull from Sierra Leone, collected long ago by Mr. T. 

 Whitfield, but only recently rendered available for comparison. 



The additional material shows, as is not surprising, that 

 Emin's specimens, while excessively like A. africana in their 

 external appearance, differ so much in cranial characters as 

 to necessitate their specific distinction. 



The species may be called 



Atherura centralis^ sp. n. 



Size, colour, and other external characters very much as in 

 A. africana.^ except that the spines are rather more fimbriated, 

 and those of tlie sides are more frequently tipped with white. 



Skull longer and slenderer, with a flatter, less inflated, and 

 narrower frontal region and better defined postorbital pro- 

 cesses. Anteorbital foramina higher than broad, the converse 

 being the case in A. africana', posterior edge of the base 

 forming their lower boundary level with or in front of the 

 front edge of the anterior cheek-tooth, whether mpj^ or 

 p^ ; posterior edge of palate level with the middle of the last 

 molar in place, whether m.'^ or m.^, according to age. 



Teeth remarkably small and delicate, the length of the 

 upper molar series scarcely more than half the diastema, while 

 in the allied species this measurement is about two thirds of 

 the diastema. The small size of the teeth is, of course, the 

 reason for the relatively different position of J9.* and the ante- 

 rior zygoma-root. 



Dimensions of the type, marked by Emin as a male (in 

 skin) : — 



Head and body (c.) 500 millim. ; (tail imperfect) ; hind 

 foot 60. 



Skull : basal length 86, basilar length from henselion 78; 

 greatest breadth 46 ; nasals, length 28 ; interorbital breadth 

 26'8 ; intertemporal breadth 24*5 ; anteorbital foramen, 

 height 10, width 8, distance between most distant points of 

 the two foramina 35; palate length from henselion 41-7 ; 

 diastema 27*7 ; upper molar series (crowns) 15"3. Length of 

 lower jaw, bone only, 59; condyle to angle 21*6; length of 

 lower molar series 16'8. 



Hah. Monbuttu, Central Africa. Coll. Dr. Emin Pasha. 



Tyi^e: B.M. 87.12.1.98. 



The main cause for distinguishing the Central- from the 

 West- African Atherura lies in the extremely small size of the 

 molar teeih, a characteristic equally observable at all ages. 

 This latter is a point which lias to be especially noticed in 

 studying the teeth of porcupines, owing to the peculiar manner 

 in which wear affects the size of the teeth. 



