NORTHUMBERLAND AND DURHAM. 213 



me that the description given him by Professor Zeller, one of 

 the first Lepidopterists of the day, of the larv^ feeding on the 

 same Erodium from which he bred Agestis, as mentioned in the 

 '' Proceedings of the Entomological Society," vol. ii., N.S., p. 

 107, agreed entirely with that of Artaxerxes ; and as the one 

 statement is the result of written description Ly so skilful and 

 accurate a describer as the learned Professor, and the other only 

 of recollection, I think we must be guided by the former. It is 

 certainly a curious coincidence that, in both instances, these 

 larvae should all have been found feeding on the same plant, and 

 that, too, in localities so far apart as Kent and Glogau, and cer- 

 tainly is prima facie an argument for their specific distinctness, 

 since the larvae of the Diurna are not usually general feeders 

 like those of many of the Heterocera. Still, I think, when I come 

 to consider the locality in which this southern form is met wdth, 

 it will appear very probable that, in this case, the Helianthemum 

 is equally a food plant. 



Of our own local insect I regret the larva has not yet been 

 found, though, if diligently sought for on the Helianthemum^ by 

 some of our members resident near the place of its occurrence, I 

 anticipate its certain discovery. This is particularly desirable 

 from the fact that our specimens assume the characters both 

 of the Agestis of the South, and of the Ai^taxerxes of the North, 

 and therefore may reasonably be presumed to exhibit the differ- 

 ences, if any, existing in that state. Dr. Lowe, of Edinburgh, 

 in a paper read before the Royal Physical Society, a copy of 

 which I owe to his kindness, details his unsuccessful attempt to 

 find the chrysalis when at Castle Eden Dene, in 1855 ; and after 

 learning Mr. Plarding's discover}' , as above-mentioned, is inclined 

 to predict that the larva will be found to feed on Geranium san- 

 guineum, which, as he noticed, and as is well known, grows there 

 in abundance. In this, I think, he is decidedly mistaken ; for 

 that plant grows in other parts of our district, where Salmacis 

 has certainly not been met w^ith, and is certainly wanting in 

 others w^here the insect is found. I have not the slightest 

 doubt but that, like Artaxerxes, the Helianthemum will as surely 

 prove to be its food as its presence indicates the place of flight. 



VOL. III. PT. IV. 1 c 



