introduction. 
93 
for geographic illustration is entirely new. The 
bird-skins of Senegal, indeed, have long been made 
an article of traffic with this and other countries, and 
hence the descriptions of many species will be found 
scattered in our systems. But these, comparatively, 
are few, and there is as yet no connected account of 
this geographic division of the African continent, 
although it is unquestionably the richest in point of 
splendid colouring, and inferior to none other in 
scientific interest. 
A more general and accurate idea of the pecu- 
liarities of this portion of African ornithology will 
be gained, by taking a rapid glance at those of the 
northern and southern extremities. The long line of 
coast bordering on the shores of the Mediterranean, 
as we have just remarked, has never been suffi- 
ciently investigated ; hut we know that those coun- 
tries are the extreme limits of several groups, of 
which no species are to he found on the opposite 
shores ; while, on the other hand, very many are 
common to both. Of these latter, the most remark- 
able are migratory ; passing from the African conti- 
nent to the south of Europe in the spring, and 
returning there in the autumn. It is from among 
these migratory tribes that Europe derives the 
greater part of her most gaily coloured birds ; such 
as the common bee-eater ( Merops Europcew ), the 
golden oriole ( Oriolus galbula ), the European 
roller ( Coracias garrvlm J, the common hoopoe, 
and several others less striking. These large flocks 
are followed by several species of the falcon and 
