CHAP. X.] THE PALZARCTIC REGION. 215 
Ethiopian districts of Senegal and Gambia to the east. There is 
a mingling of the two faunas, but the preponderance seems to 
be undoubtedly with the Palearctic rather than with the 
Ethiopian. I owe to Mr. R. B. Sharpe of the British Museum, 
a MS. list of the birds of these islands, twenty-three species in 
all. Of these eight are of wide distribution and may be ne- 
glected. Seven are undoubted Palearctic species, viz. :—MMilvus 
ictinus, Sylvia atricapilla, S. conspicillata, Corvus corone, Passer 
salicarius, Certhilauda desertorum, Columba livia. Three are 
peculiar species, but of Palearctic genera and affinities, viz. :— 
Calanoherpe brevipennis, Ammomanes cinctura, and Passer jago- 
ensis. Against this we have to set two West African species, 
Estrilda cinerea and Numida meleagris, both of which were 
probably introduced by man; and three which are of Ethiopian 
genera and affinities, viz.:—Halcyon erythrorhyncha, closely 
allied to H. semicerulea of Arabia and North-east Africa, and 
therefore almost Palearctic; Accipiter melanoleucus; and Pyrrhu- 
lauda nigriceps, an Ethiopian form; but the same species occurs 
in the Canaries. 
The Coleoptera of these islands have been also collected by 
Mr. Wollaston, and he finds that they have generally the same 
European character as those of the Canaries and Madeira, several 
of the peculiar Atlantic genera, such as Acalles and Hegeter, 
occurring, while others are represented by new but closely allied 
genera. Out of 275 species 91 were found also in the Canaries 
and 81 in the Madeiran group; a wonderful amount of similarity 
when we consider the distance and isolation of these islands 
and their great diversity of climate and vegetation. 
This connection of the four groups of Atlantic islands now 
referred to, receives further support from the occurrence of land- 
shells of the subgenus Leptaxis in all the groups, as well as in 
Majorca ; and by another subgenus, Hemicycla, being common to 
the Canaries and Cape Verd islands. Combining these several 
classes of facts, we seem justified in extending the Mediterranean 
sub-region to include the Cape Verd Islands. 
