CATALOGUE OF BUTTERFLIES. 13 



must be taken that at present we have no trustworthy record 

 of the oceurrence of Argiolus in iN'orthumberland. In Mr. 

 Barrett's new work he states that it is found in T^orthumber- 

 land, but he informs me that the statement is made only on the 

 authority of Mr. Hodgkinson's erroneous record. 



12. P. Alsus (W. Y., I'ab.). Small Blue. 



Polyommatus Alsus. Staint. Man., vol. 1, p. 57. 



„ ,, Barrett's Lep. Brit. Is., vol. 1, p. 92. 



LyccBna ,, JSTewm. Brit. Butt., p. 134. 



Laeta. Buck., vol. 1, pi. xiv., fig. 2. 



This, the smallest of the British, but not of the European 

 Blues, occurs in several places in the county of .Durham. It is 

 not in the Twizell list, but is mentioned in the introduction as 

 occurring at Twizell, and one specimen was in the collection 

 when it was examined for me some years ago, for the purpose 

 of this catalogue. This is the only evidence I have of its 

 occurrence in ^Northumberland, but it is so very local an insect 

 and flies for so short a time, that, being so small- also, it may 

 easily be overlooked. It should be sought for in the last week 

 in June or first in July, near where the food plant, Anthyllis 

 vulneraria (Kidney Yetch) abounds. It is not on the wing 

 longer than a fortnight, and is particularly fond of damp grassy 

 hollows near its food plant. Wailes says, '' Marsden — "Witton- 

 le-Wear — Castle Eden Dene — old coal heap opposite Wylam — 

 Shull. — "Wm. Backhouse, Esq." The only note in Mr. Back- 

 house's paper is ''Shull;" I conclude, therefore, as with the 

 last species, that the first four localities are given on Mr. 

 Wailes' own authority. Ornsby's Durham gives " Castle Eden 

 Dene, Eagpeth near Elass." Mr. Maling found it at Witton- 

 le-Wear, and also on Railway banks near Marsden. I found it 

 over 30 years ago at the southern extremity of Black Hall 

 Eocks. It disappeared from there and I saw no more of it for 

 many years, but it turned up again in great abundance in 1885, 

 some two or three miles further north. In 1892 I found so 



