2432 The Zoologist — January, J 871. 



'Practical Entomologist,' vol. i. pp. 10 — 12 and 37, 38) on the 

 subject of this insect being a true gall-mal<er: 'We are now fully 

 persuaded that the idea originally entertained by Dr. Harris and 

 Dr. Fitch, and subsequently fiivoured by the senior editor of this 

 journal, namely, that these galls are in reality made by some undis- 

 covered gall-gnat, upon which the so-called joint-worm is a parasite, 

 is a false and fallacious one. Both Harris and Fitch afterwards 

 became of opinion that the joint-worm fly was the real author of 

 these galls ; and wc think it right to bear this public testimony to 

 the correctness of their entomological inferences.'" 



Dr. Walsh then argues at length that there is only one American 

 joint-worm fly, and that the Eurytoma Hordei of Dr. Harris and 

 three species instituted by Dr. Fitch arc merely varieties of one 

 and the same species. The four so-called species are : — 



1. The Joint-worm Fly [Einyloma Tritici, Fitch). On wheat. 

 Front shanks dull pale yellow; middle and hind shanks black. 



2. The Rye Fly {Euryloma secalis, Fitch). On rye. Front and 

 hind shanks dull jjale yellow; middle shanks black. 



3. The lilack-legged Barley Fly [Euryloma Hordei, Harris). 

 On barley. Front shanks of the same dusky or blackish colour 

 as the middle and hind ones. 



4. Tiie Yellow-legged Barley Fly {Euryloma Julvipes, Fitch). 

 On barley. Ergs, including all the shanks, bright tawny yellow. 



Dr. Walsh, lastly, writes at length on the unity of habits in 

 insects and other animals, and observes that there is no exception 

 to this law in the case of the joint-worm fly, for it belongs to the 

 genus Isosoma, and not to the parasitic genus Eurytoma. 



In the 'Canadian Entomologist' (vol.ii. p. 25, November, 1869), 

 Mr. W. Saunders writes: — "In vol. i. p. 20, of the 'Canadian 

 Entomologist,' I published a dcsciiplion of a larva found in- 

 I'esting the seed of the gra])c, and in the ' Canada Farmer' for 

 October 15, 1868, page 316, a fuller description of its habits and 

 destructive powers, and. ventured the opinion that it would probably 

 produce, when mature, a small Curculio. In this I was in error, 

 for the perfect insect proves to be Hymenopterous, a small four- 

 winged fly belonging to Isosoma, and, as it is believed to be 

 undcscribed, I propose for it the name of I. Vitis." 



This paragraph is followed by some observations on its economy 

 and a description of the species. 



The following extract is from Mr. Riley's ' Second Report on the 



