30 On the Distribution of European Birds. , £Jan. 



tribe is not at all well developed, at least to such a degree as to account 

 for its extensive distribution. Nor does this remark apply to this group 

 alone, many other examples, if it were necessary, could be given. In 

 regard to the Eagles, Mr. Swainson's statements are equally in- 

 accurate. Thus of the nine Eagles included in the genera Aquila, 

 Halketus, Pandion, and Circaetus, two are common to Europe, Asia, 

 and Africa ; one common to Europe and North America ; one common 

 to Europe and Asia ; one common to Europe and Africa ; two 

 common to Europe, Africa, and North America; one cosmopolite ; 

 leaving only one proper to Europe; for it seems not at all improbable, 

 that the Aquila imperialis will be found extending throughout the 

 African Continent. 20 Moreover it may be stated as a general rule, that 

 in whatever families we observe a large series of modifications, 

 there we have a wide distribution. This is strikingly the case in 

 the Falconidce, Anatidce, Sylviadce, Muscicapidce, Columbidce, 

 Fringillidce, Laridce, Turdidce, Laniadce, &c. Nor is this rule 

 confined to the ornithological kingdom ; we have a similar arrange- 

 ment exhibited in the mammalogical, as well as in many of the other 

 kingdoms of the organic world ; and when we direct our attention to 

 the inorganic, we can trace out a similar arrangement. Thus in 

 those families in the mineral kingdom in which the physical and 

 external characters are very various, in them we find a most extensive 

 distribution, as is well exemplified by the quartz, calcareous spar, 

 and garnet families, modifications of which occur in every formation, 

 from the oldest up to the newest ; in every climate, from the inhos- 

 pitable regions of Melville island to the tropics, and in all the inter- 

 mediate spaces ; and, on the other hand, from the tropics as far south 

 as 70°, and also at all heights and depths yet attained by man, 

 viz. from 20,000 feet above, to 1600 feet below, the level of the sea. 26 

 In regard to the nocturnal birds of prey, comprehended in the genera 

 Strix, Bubo, Otus, Scops, Surnia, Uhda, Syrnium, and Noctua, we 

 have the following statement to make, which is quite at variance with 

 that given by Swainson. Thus of the fifteen Owls found in Europe, 

 three only are proper to it, one of these doubtful; common to 



25 Mr. Gray, m General Harclwicke's Work on Indian Zoology has figured a bird 

 under this name, which however is quite a different species. The specimens noticed 

 in the Asiatic Society's Journal for November, 1838, as varieties of the Aquila chrys- 

 aetos by Dr. Evans, are quite different birds ; in fact they do not belong to the genus 

 Aquila at all, being characteristic specimens of the genus Halicetus. The bird is a 

 new species, and the only other specimen we have seen is in the collection of 

 the Zoological Society, London. 



26 Jameson's manuscript Lectures on Miner, see also Man. and Syst. of Mineralogy. 



