470 



APPENDIX I 



It was first described from Lapland, and is very common in Lab- 

 rador, but occurs nowhere else in America. It is a narrow, slender 

 insect one-quarter of an inch long, yellowish brown, with the head 

 and a band across the thorax (or middle portion of the body) 

 black. The wing cases are quite rough and uneven. 



The other beetle which 1 

 sought in the beginning from 

 my Labrador friends (Agabus 

 infuscatus Aube) is appar- 

 ently even more common 

 there than the one in the 

 illustration. It has been re- 

 corded from Mount Wash- 

 ington and Lake Superior, 

 but it is certainly not com- 

 mon at either of these points. 

 It is shorter and more robust 

 than Agabus arcticus; the 

 wing covers are brown, the 

 head and thorax black. 



The large water-beetle 

 shown in the next figure (No. 

 22 Dytiscus dauricus Gebl) 

 is one of the largest of the 

 Labrador beetles, being an 

 inch and a quarter long. It 

 is greenish black, with the 

 borders of the thorax and of the wing covers yellow. The under side 

 of the body is yellow, with several black lines and markings. The 

 beetles of the genus Dytiscus are probably the most highly devel- 

 oped of all beetles. The males have the three basal joints of the 

 front tarsi (the last segment of the leg) enormously dilated and 

 enlarged into a large circular disk, the under side of which is cov- 

 ered with a large number of palettes, some large, some small. The 

 middle legs are similarly modified, but to a less degree. These 

 disks are of use in enabling the beetle to cling to objects, and are 

 probably also very sensitive organs. The females do not have 

 these disks at all, but, on the other hand, they often have deep 

 grooves or furrows extending longitudinally halfway or more along 

 the wing covers. 



While speaking of water-beetles, it is interesting to note that 

 they all possess real wings and are capable of flying great distances. 

 In countries where there are artificial lights, the beetles are often 

 attracted to them and are sometimes found many miles away from 

 any water. 



FIG. 22. 

 Dytiscus dauricus. 



