A LIST OF THE DIITERA MET WITH IN WESTER ROSS 273 



135. T. cordiger, Wied., Lochinver, 24th June to 13th July 191 1 ; 



common. The first Tabanus to put in an appearance in the 

 valley of the Inver. 



136. T. sudeticus, Zeller., Lochinver, 7th to 12th July 191 1; common. 



Occurs in some numbers along the road to the Kirkaig River, 

 but is not numerous elsewhere. 



137. Chrysops relicta, Mg., Lochinver, 20th June to 10th July 191 1, 



common ; Loch Assynt (Verrall). To me it seems probable 

 that the dark Chrysops referred to by Verrall {British Flies, 

 p. 428) is the male of this species, and not C. sepulch rails, 

 as suggested. I saw no ground round Lochinver at all like 

 the places frequented by C. sepulchralis on Studland and 

 other Dorset heaths. Pleske {Ann. Mus. Zoo/. S. and P., 

 xv. (19 10), p. 436) has apparently overlooked Yerrall's 

 remarks regarding C. sepulchralis and C. maurus, and the 

 probability of these two names being synonyms for one 

 species. Previous to the above record, I had not met with 

 any species of Chrysops to the north of Nairn. 



THEREVIDiE. 



138. Thercva arcuala, Lw., Golspie (Verrall). 



139. T. nobilitata, F., Golspie (Verrall). 



140. T. plebeia, L., Golspie (Verrall). 



141. T. bipunctata, Mg., Golspie (Verrall). 



142. T. atinulata, F., Sutherland (Verrall). 



Though Thereva is a common genus at Golspie, it seems 

 to be quite absent from the neighbourhoods of Lochinver and 

 Inchnadamph ; this may be due to the paucity of broad- 

 leaved trees, and in the case of T. annulata and bipunctata, 

 to the absence of murrain grass and sand-dunes. 



Asilid.k. 



143. Isopogon brevirostris, Mg., Lochinver, 24th June 191 1, in fair 



numbers, sitting on stones in an inclosure marked on the 

 Ordnance Survey map as " Market Site " ; Loch Maree 

 (Verrall). Lochinver on the west coast, and Golspie on the 

 east, seem to be the northern limit of what may perhaps be 

 called the southern fauna; this species and the next reach 

 their northernmost boundary at these two places, and many 

 other conspicuous southern insects seem to do the same, e.g., 

 Brachyopa bicolor, Leucozona lucorum, Chrysops relictus, 

 12 2 M 



