326 Mb BNTOMOLoCtlST. 



excellent work on the * Geographical Distribution of the Swiss 

 and German Lepidoptera.' The only differences are, first, the 

 addition of" the olive zone, which occurs on the south side of the 

 Alps, namely, in sheltered valleys at the foot of the Maritime, 

 Pennine, and Lepontine chains; and, secondly, the division of 

 Messrs. Speyer's lower region into those of the vine zone and 

 lower hill zone respectively. These two additional zones are 

 necessary on account of the unfair value which is attached to 

 Messrs. Speyer's lower zone ; besides, they represent two very 

 important climatal belts, — the olive zone terminating polewards 

 at the annual isotherm of 5i'5° F., and the vine that of 50° F. 

 This arrangement harmonises with that given in my article " On 

 the Vertical Distribution of the British Lepidoptera " (Entom. 

 xxvii. pp. 2, 27), to which I beg to refer the reader who desires 

 to know the British equivalents for the vertical zones in the 

 Alps, also their mean annual temperature. 



The olive zone is very well defined in the Alps, and receives 

 its greatest development on the south side of the Maritime chain 

 in the Gulf of Lyons and the neighbourhood of Nice ; but there 

 are several spots where it occurs also in the Pennine and Lepon- 

 tine chains, especially at Bellinzona in the canton of Ticino, where 

 the land sinks to the comparatively low elevation of 646 ft. above 

 the sea-level. The vine zone is also clearly defined, but the 

 boundary between the one above, namely, the walnut or lower 

 hill zone and that of the beech or upper hill zone, is very difficult 

 to discern, except to an experienced botanist. All the other 

 zones are, however, easy to identify by reason of the very 

 distinctive character of their vegetation. In some parts of the 

 Alps, though, I may here observe, on account of the .ruthless 

 destruction of many of the more extensive forests of deciduous 

 trees the conifers have taken their place, and thus frequently 

 occur at a lower elevation than the proper region to which they 

 belong. The character of the accompanying vegetation will, how- 

 ever, help one to determine the zone with sufficient accuracy for 

 our purpose. 



The olive zone is the equivalent of the warm temperate region 

 of the horizontal isotherms, while the vine, the lower hill and 

 the upper hill zones represent the cold temperate region ; the 

 lower alpine, the sub-arctic ; the upper alpine, the arctic ; and 

 the snow zone, the polar regions, respectively. By means of the 

 preceding table the entomological student, who only possesses a 

 rudimentary knowledge of botany, may be able to tell at a glance 

 the particular zone that he is in by the general aspect of the 

 vegetation by which he may be surrounded. For the list given 

 I am indebted to the admirable and learned compilation on the 

 ' Natural History of the Alps,' by that veteran traveller I. von 

 Tschudi. As regards the scientific importance of a knowledge of 

 the vertical distribution of the Rhopalocera, and its value in 



