1907]. ^^ 



captured in Inverness-shire, and had considered to be a new species, 

 and not Ornithomyia avicularia, the common bird-fly. Very soon 

 after the reception of the Caithness specimens Mr. Shipley returned 

 from Blair AthoU, i.i North Perthshire, where he had been making 

 some investigations in connection with the grouse disease, and he 

 handed over to me a small series of grouse-fly, which proved to be 

 the same as those sent by Mrs. Duff Uunbar. 



On investigation of the literature I find no record of the occur- 

 rence of any species of Ornithomijla on grouse other than O. avicu- 

 laria, and I have, therefore, no hesitation in giving a name to the 

 form that occurs in the northern parts of Scotland in connection with 

 the peculiar bird, Lagopus scoticus. 



Oenithomtia laqopodis, sp. n. 

 Supra nigricans, siihtus pallide testacea, pedibus fusco-tcstaccis ; pectore^ 

 utrinquejusco-nigro-hiplagiato. Long, corp., 5 mm.; expans. alarum, \l\ 



7 / ■ c „„, Hah., Scotia, 



mm., long, alee sing., 5 mm. 



Smaller than 0. avicularla, distinguished by its peculiar lurid blackish colour, 

 without a.iy trace of green even on the feet or legs ; the rostrum is black, and the 

 hairs of the body and appendages are shorter than in the better known form ; on 

 each side of the thoracic pleuron, between the front and middle legs, there is a very 

 large dark patch extending as far towards the middle as the base of the front coxa, 

 and divided into two parts by an oblique pallid line. The head is considerably 

 smaller and narrower than that of O. avicularia, and has beneath a very large area 

 of smoky colour on each side. 



f4i:. Mr. Collin has pointed out to me that the segments, or abscissae, 

 of the costa afford a good character; the relative lengths of the 

 outer two being in O. la<jopodis as 9-8, and in C. avicularia about 

 12 or 12i-8. The bristles on the scutellum are usually more 

 numerous, as well as larger, in 0. avicularia. 



There is very little information as to the variation of O. avicu- 

 laria in connection with the birds it dwells on, and great difference of 

 opinion exists as to the value of species that have been proposed, but 

 scarcely established. This subject has recently been discussed by 

 Dr. Speiser, and I need not refer to it further than to say that Bezzi, 

 in the recent catalogue of Palsearctic Diptera, recognises O.fringil- 

 lina, Curtis, as a distinct species, so that with 0. lagopodis we have 

 now' in Britain three forms that can be fairly well discriminated. 

 Mr. G. H. Verrall tells me that he thinks we have even a greater 

 variety than this, but that he has not been able to progress with their 

 discrimination for want of series of specimens and of information 

 about them. 



