Utility of Arnotfs Stove in Green-houses. 107 



your late articles. This gentleman forwarded to me leaves of 

 chrysanthemums during the past summer, of which patches 

 were dried up, precisely similar to those of the celery leaves ; 

 the larva which produced the mischief was similar to that of the 

 Tephritis onopordinis, and it underwent its changes in a similar 

 manner, so as to render a detailed description unnecessary. 

 Whilst feeding, I observed, through the transparent surface of 

 the leaf, that it used the two bent hooks or mandibles, which it 

 has the power to retract within or protrude from the mouth, 

 like a pair of scrapers, or rather like the instrument known to en- 

 tomologists under the name of the digger. By this action the 

 parenchyma was entirely destroyed, and brought into a state to 

 pass into the mouth of the larva without difficulty. 



The perfect insect appeared in the month of August. It is 

 about the same size as the preceding, and prettily marked, but 

 is not so elegant a fly as the other. It belongs to the 



Genus, Tephritis. 



Subgenus, Acidia? Rob. Desvoidy and Walker. 



Species, Tephritis (Acidia ?) artemisiae Fabr. (Fig. 22. G, magnified.) 

 Presumed varieties : Trypeta artemisiae, alternata, continua, intermissa, and 

 abrotani, Meigen. ( Walker in Entomological Magazine, No. xi. p. 84.) 



It is of a pale yellowish buff colour, with a few black hairs, 

 especially at the sides of the thorax ; the wings are limpid, but 

 slightly tinged with yellowish, having several black spots of 

 various shape and size, forming three uninterrupted bands across 

 the wings. 



The modes suggested for the destruction of the preceding 

 species are equally applicable to the present. 



In the magnified figures, one wing is represented unspotted, 

 in order to show the disposition of the veins. 



Art. III. On the Employment of Arnott's Stove for heating Green- 

 houses. By T. Rivers, Jun. 



Having recently built a new green-house, and feeling un- 

 willing to incur the expense of fixing a hot-water apparatus, yet 

 anxious to spare the great expenditure of fuel, occasioned by 

 brisk flues, my attention was turned to Arnott's stoves as a 

 medium. Accordingly, early in last December, I procured 

 from Cottam and Hallen, one of their 18 in. stoves, which is now, 

 and has been since then, in constant operation. My new house is 

 60 ft. long, by 12 ft. wide, with a span roof; the stove is placed at 

 one end, within a few feet of the door. To explain why I had it 

 placed at the end, rather than in the centre, let me here say that, 

 feeling rather sceptical as to its efficacy in engendering sufficient 



