56 FOREST PLIES. 



and rub lightly over the animal, particularly the parts beneath and 

 under the tail, which are most subject to infestation. 



In tlie above notes I have only entered shortly on some of the 

 main points regarding this infestation, which I have given in detail at 

 pp. 95-1 17 of my Nincteentli Annual Keport. In this will be found 

 my own observations on the elaborate structure of the foot appendage, 

 and many notes from life regarding habits of the fly and remedial 

 treatment used in the New Forest, as well as abstracts regarding the 

 existence in embryo from the observations of Reaumur, and references, 

 confirmatory observations of De Geer, and references to the elaborate 

 considerations of Leuckart, and notes from other entomologists. There 

 I have also given some observations on the Dog Forest Fly, Hijijwbosca 

 canina, Rondani, also of the Indian or Spotted Forest Fly, Hippobosca 

 maculaUi, Leach, which were placed in my hands in the course of the 

 investigations of 1895, and are of considerable interest as being of 

 nearly-allied Hippoboscidce. 



Spider Ply; Grouse Ply. 



Ornithomyia avicularia, Linn. ( = viridis, Meigen). 



On September 29th I was favoured by Mr. E. G. Wheler, of Swans- 

 field House, Alnwick, Northumberland, with a specimen of a "Forest" 

 or " Spider " Fly taken from a grouse, with the remark accompanying 

 that he forwarded it, as it might be of interest relatively to some 

 difi'erence which he noticed in the structure of the claws of the speci- 

 men and those of the nearly-allied Horse Forest Fly, Hippobosca equina. 



From the wings of the specimen being folded longitudinally under 

 the covering glass of the microscopic slide, it was not possible to 

 investigate the neuration thoroughly, but other characteristic points 

 were so well displayed that (after consultation) there did not seem to 

 be room for doubt that the specimen was Oniithonii/ia avicularia, 

 Linn., sometimes also known as viridis; this, more especially as 

 O. avicularia, L., is the only species recorded as British in the ' List 

 of British Diptera ' by G. H. Verrall, F.E.S., 1888. 



On October 25th, in reply to my mention that a few more speci- 

 mens would be very acceptable if easily procurable, Mr. Wheler was 

 good enough to send me two more, preserved in spirit, with the 

 observation : — 



" I have no opportunity of obtaining more Grouse Flies now, and, 

 in fact, think it very probable that they are only about during the hot 

 weather, as they are very active, and by no means easy to catch when 

 they leave their host. ... I took the Grouse Flies from freshly- 



