THE GENUS ITHYSlA. 315 



hecla, which was in such abundance that I selected over sixty 

 perfect specimens in a few-hours out of perhaps three times that 

 number netted. It will be understood what a treat it was to a 

 lepidopterist to see the swarms of this beautiful species, after a 

 week of storm and rain, passed chiefly in a Lapp hut, with a 

 diet of, for the most part, sweet coarse rye bread and goat- 

 cheese. 



My return journey to Kolvik, on July 17th, also nearly 

 resulted in disaster, for at one of the two rivers which have to be 

 crossed in a ferry-boat a cord slipped just as the cart containing 

 the whole of my possessions was being got aboard, causing it to 

 slide down the bank — which shelved rapidly — into the water 

 and to come within an ace of being engulfed. By strenuous 

 exertions, however, the driver and I managed to get my luggage 

 out and placed in safety on the bank just in time. 



(To be continued.) 



THE GENUS ITHYSIA (Hubner). 

 By J. W. H. Harrison, B.Sc. 



As Mr. Prout has shown that the correct generic name of 

 this group is Ithysia, I am adopting it in place of the more 

 commonly used Nyssia (Dup.), which includes, in addition, the 

 species I have included in my genus Poecilopsis. 



It was not my intention to supplement my notes on the 

 Bistoninae, published in the ' Entomologist ' for July, 1910, 

 until I had completed my work on the group, but I have been 

 compelled by force of circumstances to publish the result of my 

 investigations on this genus. As the genus now stands in our 

 lists, it includes the three species, Ithysia zonaria, I. alpina, and 

 I. grcecaria, or, as we now call them, Nyssia zonaria, &c. ; but I 

 find that there are four species in the genus. These are : — 



Ithysia zonaria (Schiff.). 



I. alpina (Sulzer). 



I. italica, sp. n. 



I, (jfrcccana (Bdv.-Staudinger). 



To simplify the descriptions of the species it will be well to 

 give here the scheme I have adopted in dealing with the various 

 hybrids I have reared in this family. 



I look upon the fore wings in the " ideal " species as being 

 crossed by three transverse lines, which may or may not be 

 obsolete in any given specimen. The first three, viz. first, 

 median, and second, are dark coloured. The fourth or sub- 

 terminal I look upon, for the sake of simplicity, as the white or 

 pale band, which is generally followed or preceded by a strong 



