50 THE SCOTTISH NATURALIST 



Specimen for his museum, especially when an opportunity 

 was afforded by the stranding of a rare Cetacean on the 

 Scottish coasts. Particulars of some of these occurrences 

 were contributed by Sir William to our pages. 



From time to time the inhabitants of dwelling-houses 

 have been annoyed by the appearance of swarms of flies in 

 one or other of their apartments, the swarm sometimes con- 

 sisting of several thousands of individuals, and occasionally 

 recurring year after year in the same room. The chief 

 offender in most cases appears to be a two-winged fly — one 

 of those pretty little black and yellow striped flies known as 

 Chloropid^e, but other families also contribute to the 

 nuisance, notably the true Muscidae, occasionally Antho- 

 myiidse, and even the tiny Psocidae, which belong to a 

 totally different order of insects, viz., Neuroptera. In this 

 connection a very interesting note (worthy of larger type ! ) 

 appears from the pen of Hugh Scott, of the Cambridge 

 University Museum of Zoology.^ Accompanied by Dr A. 

 E. Shipley, the author recently paid a visit to a house near 

 Cambridge and had the opportunity of inspecting one of 

 these interesting but unwelcome visitations. The rooms 

 concerned were the drawing-room on the ground floor and 

 one immediately above. The appearance of the swarm is 

 described as a " trul)- astonishing sight. In the large bay- 

 window every pane of glass was densely covered with 

 countless myriads of small flies : on the upper sides of the 

 projecting cross-pieces of wood between the panes the flies 

 rested in masses, literally crawling over each other, while all 

 the part of the ceiling near the window was almost as 

 thickly covered as the window itself" An investigation 

 of the swarm proved that the principal constituents were 

 the Chloropid known as CJdoropisca ornata and a species 

 belonging to the family Anthomyiidae.- A {^\\ days pre- 

 vious to the visit the former much smaller fly prepon- 

 derated, but later the Anthomyiid became the dominant 

 species. Several other kinds of flies were found, but in 



^ Ent. Mo. Mag., January 1916, pp. 18-21. 



'^ Since identified as Limnofihora 7-nofafa^ Ztt. (Ent. Mo. Mag., 

 February 1916). 



