Petrodromus and Rhynchocyon. 365 



lower flanks with only a slight indication of the buffy so 

 strongly developed in this region in tetradactylus. Under 

 surface as white as in venustus, not washed with buffy, as 

 is usual (though not invariable) in tetradactylus ; chin, how- 

 ever, of the single specimen quite buffy. Facial markings 

 less developed than in tetradactylus, the light line over the 

 eye broader, vaguer, and less sharply contrasted ; the usual 

 large continuous dark patch behind it broken into two and 

 much less conspicuous. Upper surface of hind feet pale 

 brown, as in tetradactylus, not so whitish as in venustus. 



Skull as in tetradactylus, with average palatal vacuities. 



Dimensions of the type (taken by collector in the flesh) : — 



Head and body 191 mm.; tail 155; hind foot 56 (also 56 

 dry) ; ear 37. 



Skull: greatest length 52 - 4 ; condylo-basal length 50; 

 zygomatic breadth 27 ; upper tooth-series 27*5. 



Hob. (of type). Manguzi, N.Zululand (6 miles from coast 

 and about the same distance south of the Portuguese frontier). 



Type. Young adult male. B.M. no. 18.4. 9. 1. Original 

 number 86. Collected November 1905 by Mr. Toppin for 

 the Natal Museum, and presented to the British Museum by 

 the latter. 



This Petrodromus differs from true P. tetradactylus by its 

 much greyer and less buffy coloration and its less conspicuous 

 m face-markings. In distribution it would seem to be separated, 

 so far as we know at present, from the area of tetradactylus 

 by about 6 degrees of latitude, that animal not being hitherto 

 recorded south of 21° S., while the inteimediate area is 

 occupied by P. (Cercoctenus) schwanni. 



In connection with the determination of the Zululand 

 Petrodromus, I have made a renewed examination of the 

 considerable series in the Museum, with a view to finding 

 out how far Mr. llollister's * recent erection of a genus for 

 P. sultan and sclncanni, the species with bulbous tail-bristles, 

 is supported by this material, and especially what is the 

 biaring on this distinction of P. rovumos, so intermediate 

 between the others in its essential characters. 



Of the characters of " Cercoctenus'''' recorded by Hollister, 

 those of the bulbous bristles and less imperfect palate are 

 undoubtedly valid, but those drawn from p 1 and p 4 do not 

 appear to be at all constant — the "spikelet" on p l is present 

 in several of our P. sultan and many of our P. schwanni, 

 while the reputed greater complexity of p 4 is not true as 



* Smiths. Misc. Coll. vol. lxvi. p. 1 (1916). 



