A LIST OF THE DIPTERA MET WITH IN WESTER ROSS 271 



apparent, though such disappears within a very short period. At this 

 early age they spend from five to eight seconds submerged, which 

 period increases to ten to fifteen seconds at ten days, and in propor- 

 tion at other ages ; but the depth of water has a modifying influence. 

 They are nearly full-grown when five weeks old, and are able to fly 

 at six weeks. 



A LIST OF THE DIPTERA MET WITH IN 

 WESTER ROSS, WITH NOTES ON OTHER 

 SPECIES KNOWN TO OCCUR IN THE 

 NEIGHBOURING AREAS. 



By Colonel J. W. Yerbury, R.A., F.Z.S. 

 {Continued from fage 232.) 



ORTHORRAPHA BRACHYCERA. 



Si ratiomyid 1 . 



106. Oxycera nigripes^ Inchnadamph, June and |uly 191 1: in 



numbers (Verrall). Mr Venal] found this species common 

 in a wet spot on the banks of the river Tarragill, near Inchna- 

 damph. Although I believe I found this exact spot in 191 1, 

 the species was quite absent j it occurred, however, in 

 abundance on the banks of the burn running down from 

 Ardmore. It seems to be doubtfully distinct from O. 

 pygmcea. 



107. Sargus fiavipes i Mg., Golspie, 13th August 1900. 



108. S. ruffes, Wahlb., The Mound (Verrall). 



109. S. iridatus, Scop., Golspie, 29th and 31st July 1900. 



no. Chloromyia formosa, Scop., Golspie, nth and 29th June 1904. 

 in. Microchrysa folita, L., Golspie, 31st July 1900. 



112. M. flavicoruis, Mg., Golspie (Verrall). 



113. M. cyaneiventris, Zett, Golspie, 13th June 1904. 



114. Berts clavifes, L., Tongue (Verrall). 



115. B. Valletta, Forst., Golspie (Verrall). 



116. B. chalybeata, Forst., Golspie (Verrall). 



117. B. geniculate Curt., Golspie (Verrall). 



118. B. morrisii, Dale, Golspie (Verrall). 



