424 Messrs. Sclater and Mackwortli-Praed on [Ibis, 



Family Corvid^. 



Heterocorax capensis minor. 



Corvus minor Schlegel, Cat. Mus. Pays-Bas, Coraces, 1867, 

 p. 27 : patr. ignot. 



Corvus capensis Licht. ; Butler, Ibis, 1905, p. 326. 



[B. coll.] 5 Malakal May, U.N. 



[C. & L. coll.] 2 Melut Jan., 1 Taufikia Jan., 1 nr. Lake 

 No * Mch. U.N. 



As was first pointed out by Heuglin, the South African 

 Hook is a much larger bird than that of the Nile valley. 

 The wings of the five examples in the Butler collection 

 average 308 mm. (299-315), while those of five birds from 

 Cape Colony average 365 mm. (355-376). Birds from the 

 Transvaal and East Africa are intermediate, but show a 

 gradual deciease in size as we travel northwards. On the 

 other hand, Abyssinian birds are very large, the only two 

 examples in the Museum measuring 355 and 358 mm. 

 respectively. 



As it seems necessary to draw a line somewhere, we should 

 he inclined to include all birds from south of the Zambesi 

 with a wing-measurement of less than 330 mm. under 

 the name //. c. capensis. Birds from the north of the 

 Zambesi to the Nile valley (except those from Abyssinia) 

 must be called H. c. minor., with a wing-measurement of less 

 than 330 mm. The Abyssinian bird will probably require a 

 new name. 



Dr. Biittikofer kindly informs us that the type of Corvus 

 minor Schlegel is still preserved in the Leyden Museum, and 

 that it resembles Heteroco7'ax c. capensis in every respect 

 except that it is so very much smaller. He gives us the 

 following measurements :— Wing 290, tail 170, culmen 50, 

 tarsus 62. It is obviously a very small bird, but not so 

 very much smaller than some of the Sudanese examples. 

 Unfortunately, it has no indication of locality. It was 



* We regret to find Lake No lias been accidentally omitted from the 

 map ; it is an expansion of the Nile at the junction of the Bahr el Ghazal 

 and the Bahr el Jebel. 



