206 ZOOLOGICAL GEOGRAPHY. [PART III. 
The Mediterranean and Atlantic Islands—The various islands 
of the Mediterranean are interesting to the student of geo- 
graphical distribution as affording a few examples of local species 
of very restricted range, but as a rule they present us with 
exactly the same forms as those of the adjacent mainland.! 
Their peculiarities do not, therefore, properly come within the 
scope of this work. The islands of the Atlantic Ocean belong- 
ing to this sub-region are, from their isolated position and the 
various problems they suggest, of much more interest, and their 
natural history has been carefully studied. We shall therefore 
give a short account of their peculiar features. 
Of the three groups of Atlantic islands belonging to this sub- 
region, the Canaries are nearest to the Continent, some of the 
islands being only about fifty miles from the coast of Africa. 
They are, however, separated from the mainland by a very deep 
channel (more than 5,000 feet), as shown on our general map. 
The islands extend over a length of 300 miles ; they are very 
mountainous and wholly volcanic, and the celebrated peak of 
Teneriffe rises to a height of more than 12,000 feet. The small 
Madeira group is about 400 miles from the coast of Morocco 
and 600 from the southern extremity of Portugal; and there is 
a depth of more than 12,000 feet between it and the continent. 
The Azores are nearly 1,000 miles west of Lisbon. They are 
quite alone in mid-Atlantic, the most westerly islands being 
nearer Newfoundland than Europe, and are surrounded by ocean 
depths of from 12,000 to 18,000 feet. It will be convenient to 
take these islands first in order. 
Azores.—Considering the remoteness of this group from every 
other land, it is surprising to find as many as fifty-three species 
of birds inhabiting or visiting the Azores; and still more to 
1 Malta is interesting as forming a resting-piace for migratory birds, while 
crossing the Mediterranean. It has only eight land and three aquatic birds 
which are permanent residents ; yet no less than 278 species have been 
recorded by Mr. E. A. Wright as visiting or passing over it, comprising a 
large proportion of the European migratory birds. The following are the 
permanent residents : Cerchneis tinnunculus, Strix flammea, Passer salicicola, 
Emberiza miliaria, Corvus monedula, Monticola cyanea, Sylvia conspicillata, 
Columba livia, Puffinus cinereus, P. anglorum, Thalassidroma pelagica. 
