20 MOSLEY : ON YORKSHIRE DIPTERA IN 1877. 



do not read these languages, and as the English books are so 

 profoundly scientific, a person has to be very enthusiastic if he (or 

 she) gets on at all. My resources have been very limited : one 

 volume of 'Insecta Britannica — Diptera,' a List of the British 

 Syrphidcd and Dolichopodidce (Ent. Mo. Mag.), a description 

 of the British species of Cheilosia (Ent. Mo. Mag.), and Mr. 

 Walker's notes on the two-winged flies (Entomologist) are what 

 I have had to guide me besides the invaluable help I have 

 received from Dr. Meade in the naming of specimens. Much 

 more progress might be made if naturalists would remember their 

 fellow workers when they are out on the many rambles they take 

 during the summer months; how easy it would be for them to 

 pick up insects they generally pass by as not worth notice, which 

 might prove very choice specimens when they come into proper 

 hands. The lepidopterist, for instance, is frequently taken in by 

 the appearance in his breeding cage of — instead of a glorious 

 Acronyda alni — a big ichneumon or dipterous parasite; in a 

 moment of vexation he generally lets the intruder feel the 

 weight of his net handle or some other instrument; whereas, if 

 he would take a little trouble to pin it and put a label on with 

 the name of the species from which it emerged, he would be 

 rendering a real service to science, and I should always be glad 

 to return lepidoptera for such consignments of diptera, which 

 need simply be pinned and labelled in the way named. I have 

 undertaken to write this paper not so much to show what has 

 been done, as to form a starting point for other workers to follow. 

 During the coming year I intend to devote my energies especially 

 to Yorkshire, and I should be very glad either to give or receive 

 any help towards making next year's list of diptera much more 

 complete than ever I should hope to do by individual aid. 



CAPTURE AND PRESERVATION. 



Beginners in a new line are very often perplexed as to how 

 they should proceed, and a word or two will perhaps serve to 

 clear away the mist some little. The lepidopterist's stock-in-trade 

 is generally sufficient" for the collecting of diptera; the gauze net 

 will be required for the capture of specimens on the wing, the 



Trans. Y.N. U., 18T7. Series D 



