546 ON A ROOK WITH AN ABNORMAL BILL. [May 11, 



that species, the hairs are slightly stained with yellow and very 

 indistinctly speckled apically. Owing to the whiteness of the 

 whiskers the brow-band is not so sharply defined at its extremities 

 as in typical C. tantalus, where the whiskers are not only much 

 shorter but are markedly stained with yellow almost throughout 

 their length. The hairs of the sides of the neck are also long and 

 mostly white, but towards the apex yellowish and speckled with 

 black. On the arm and leg the greenish tint dies out of the 

 hairs well above the elbow and knee, and it only extends for a short 

 distance upon the root of the tail ; the rest of the arms and legs, 

 the hands and feet, and the upper side of the tail being grey. As 

 in typical C. tantalus, the inner sides of the limbs, the under 

 side of the body and of the tail are white, with a patch of rusty 

 hairs upon the pubic region ; and, as in G. tantalus tantalus and 

 C. cethiops, there is a conspicuous tuft of whitish hair on each side 

 at the base of the tail above the ischial callosity. 



" Although the length and whiteness of the whiskers give 

 this monkey a striking superficial resemblance to C. cethiops, it 

 appears, as might be expected from its locality, to be most nearly 

 allied to C. tantalus, being at once distinguishable from G. cethiops 

 by the absence of white hairs from the lips and chin. Never- 

 theless, it is in a measure intermediate between the two species, 

 and to a great extent justifies my surmise (P.Z. S. 1907, p. 733) 

 that the two will be found to intergrade. 



" G. tantalus is now known to be represented by three races ; 

 namely, the typical G. tantalus tantalus from Nigeria, G. tantalus 

 alexanclri from Lake Chad, and G. tantalus hudgetti * from 

 Bathyaba on the eastern shore of Lake Albert in Uganda. The 

 last-mentioned diffei-s from the others in having the whiskers 

 much more decidedly speckled, and in the large size of the red 

 patch and the more fiery colour of its hairs on the pubic area." 



Mr. W. F. H. Rosenberg, F.Z.S., exhibited a Eook in which 

 the upper mandible had overgrown the lower to a remarkable 

 extent. This abnormality had evidently been caused by an injury 

 to the tip of the lower mandible having deprived the upper one 

 of the opposing surface necessary to check its growth. 



The bird was shot by Mr. Percy I. Lathy, F.Z.S., F.E.S., on 

 February 7th, 1909, at Nazeing, Essex. Mr. Lathy shot it out 

 of a flock, and did not notice anything peculiar till he picked the 

 bird up. The bii-d was in good condition, so that it could not 

 have had the diificulty in feeding which one might have expected 

 from the excessive prolongation of the upper mandible. 



Length of upper mandible 70 mm. ; length of lower mandible 

 51 mm. Normal length of upper mandible 55 mm. 



* Pocock, P. Z. S. 1907, p. 733. 



