DIPTERA SCOTICA : VI.- — THE WESTERN ISLES 137 



178. Eri stalls horflcola, Deg. — i $ and i ?, Butt of Lewis, 



Sept. 1914 (Eagle Clarke); Lewis, July 1914 (Lamb). 

 182. E. fefiax, L. — 2 ?, Butt of Lewis, Sept. 1914 (Eagle Clarke). 

 184. Helophllus pendubis^ L. — 8 $ and 5 $ , Butt of Lewis, Sept. 



1914 (Eagle Clarke); Lewis, July T914 (Lamb). 

 187. Serlcomyla borealls, Fin. — i $, Butt of Lewis, Sept. 1914 



(Eagle Clarke). 

 194. Bucentes genlculata, Deg. — i $ and i ?, Butt of Lewis, Sept. 



1914 (Eagle Clarke). 

 203. Cyfiomyia mortuorum, L. — 4 $, Butt of Lewis, Sept. 1914 



(Eagle Clarke). 

 208. Pseudopyrellia cornlclna, Fab. — 4 ? , Butt of Lewis, Sept. 



1 9 14 (Eagle Clarke). , 



274. Schccfiomyza lltorella, Fin. — 4 $, and 4 ?, Jura, Sept. 1907 



(Waterston) ; 5 ? , S. Uist, June 1910 (Grimshaw) ; 2 $ and 

 3 $, Balelone, N. Uist, June 1905 (Waterston). 



275. Fucellla fucorutn, Fin. — -7 $, and 15 ? , S. Uist, June 1910 



(Grimshaw). 



From the preceding list it may be noted that, as regards 

 the number of species collected in each island. Jura heads 

 the list with 166; then follow Lewis with 150, South Uist 

 with 148, North Uist with 90, and Skye with 78. Of the 

 smaller islands we have Benbecula with 27 species and lona 

 with 22. The lists for the other islands are so small as to 

 be negligible. 



I have endeavoured, by tabulating the results in various 

 ways, to ascertain whether any trustworthy conclusions can 

 be drawn from the distribution of the various species, but 

 have failed to obtain anything of a satisfactory nature. It 

 is obviously unsafe to found any deductions upon collections 

 formed by various individuals whose methods of collecting 

 no doubt varied in detail, who visited the islands in different 

 months, and who experienced different weather conditions. 

 Until the islands are thoroughly and systematically in- 

 vestigated on a uniform plan, our lists must remain unre- 

 liable for statistical purposes, and the only value one can 

 attach to the foregoing list is that of actually placing on 

 record the existence of the species on the islands concerned, 

 and of extending in a great many cases their known dis- 

 tribution in a northward and westward direction. 

 54 S 



