16 CATALOGUE OF BUTTEEFLIES. 



(Populus tremula), and by other observers on Pyriis aria and 

 Sallow, and even, rarely, upon Osier, Birch, Cherry, Pear, and 

 Apple." — Barrett's Lep. Brit. Is., vol. 1, p. 129. The scarcity of 

 Elm is not, therefore, a sufficient reason for the disappearance 

 of the species, which has probably resulted from the same causes 

 that have affected so many others. The increase of towns, and 

 manufactories, with the resulting pollution of the atmosphere 

 from smoke and chemical vapours, being among the more likely 

 agents affecting these susceptible creatures. 



Since the publication of Wailes' list, two or three specimens 

 have occurred within our district, but under circumstances that 

 tend to confirm the idea, that whatever it may have been 

 formerly, it is no longer a native of either county. A single 

 specimen was taken in a house in the village of Whitburn by 

 the late John Hancock. Another occurred at Jesmond cemetery, 

 and was captured by the late M. Henderson. The late Mr. 

 Wassermann of CuUercoats also wrote: — ^'I saw a specimen 

 of this insect sitting on the palings of my garden, which had 

 been smeared with sugar to attract moths, on the 12th Sept. 

 last" (1877).— ITat. Hist. Trans., vol. Y., p. 284. 



15. Vanessa Urticae (L.). Small Tortoise-shell. 



Vanessa Urticce. Staint. Man., vol. 1, p. 39. 

 ,, ,, I^ewm. Brit. Butt., p. 52. 



,, ,, Barrett's Lep. Brit. Is., vol. 1, p. 131. 



Lahva. Buck., vol. 1, pi. ix., fig. 2 ; Wils., pi. iii., fig. 2. 



One of the commonest of our butterflies occurring in every 

 part of the district except the higher moorlands, where the food 

 plant (Common ^Nettle) does not grow. The larvae are gregarious. 

 Barrett (Lep. Brit. Is.) says, *' May and July — August." This 

 is certainly not so in this part of the country. "We find the 

 larvae on nettles in June or July, producing imagines which 

 generally hybernate. On one occasion larvae were found near 

 Hartlepool in October, 1881, by Mr. Alfred Woods. Some 

 of these he gave me, and they produced imagines the same 



