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trac - left in the present insect fauna of the extreme southern 

 species of pre-glacial times. In this respect they agree with 

 the post-glacial mammalia, and it may be inferred from this 

 that the Ice Age must have been the factor in exterminating 

 the southern fauna. 



The relation of the Cleveland land fauna to the Ice Age 

 is one of extreme importance, and it is in this relation where I 

 think the special interest of our fauna lies to the student 

 of zoo-geography. For as Professor Kendall well remarks — 

 ' ' The whole argument concerning the history of our fauna 

 depends upon a correct and sound conclusion regarding the 

 facts of glacial geology. 1 ' Accepting, therefore, the con- 

 clusions of the glacialist as thoroughly established, we may 

 remark that the pre-glacial animals would be driven from 

 those parts of our district covered with deposits left by the 

 ancient ice. But a large part of Cleveland was never over- 

 ridden by glaciers, and the driftless area corresponds 

 roughly to the moorlands and the great dales south of the 

 main Cleveland watershed. If now we turn to Greenland, 

 which contains a comparatively numerous fauna and flora 

 living close to a heavily glaciated land surface, it seems 

 natural to infer that during the Ice Age the driftless area of 

 Cleveland supported a somewhat similar Arctic fauna and 

 flora. 



Merely noticing in passing that most of the moorland 

 plants flourish at the present day in Arctic climates, we 

 shall find that several species of insects now living in 

 Cleveland also live under the glacial conditions of Greenland, 

 and probably with various Arctic plants have existed 

 on the driftless region throughout the Ice Age. Of these 

 insects. I have so far been able to discover eight, four beetles 

 and four moths as follows : — 



Moths 



Agrotis occulta v. implicata. In Scotland and in 



Greenland. Absent from Shetland. (Spider.) 

 Plusia interragationis. In Greenland (Rink.) 

 Cheimatobia brumata. In Greenland. (Rink) 



Eupithecia nanata v. gelidata. A dark form from the 

 Shetlands, Greenland, and Labrador (Spider). 



