NOCTUA FESTIVA AND NOCTUA CONPLUA. 139 



I will now ask you to look at the series in the two drawers before 

 us. In Mr. Tutt's drawer, confhia is represented by a single row to 

 the left, fcstira by eight rows to the right of it. In my drawer, festira 

 is represented by five rows on the left, conflua by seven rows on the 

 right. A cursory glance at these series will do more to show the 

 different aspect of the two insects than any detailed description can 

 convey. 



The general appearance of large masses of the two insects is per- 

 haps best seen in my own series, as the bulk is more evenly divided. The 

 first point to catch the eye is the great difference in general colour. 

 Festira, in the mass, is of a pale brown or fawn largely suffused with 

 a light brick red. Confiua is a much darker insect, in which the light 

 brick-red is almost wanting. It may be roughly grouped into three 

 divisions, firstly, those in which the prevailing colour is a rich chest- 

 nut brown ; secondly, those which are more or less suffused with a 

 beautiful reddish-purple ; and, thirdly, those having a cold grey 

 ground. Both species vary to such an enormous extent that any 

 attempt to define each form would be a never-ending task, and only 

 tend to confusion rather than to accuracy. It will be observed, how- 

 ever, that both species vary on somewhat parallel lines. In this con- 

 nection my series shows a very important point. It will be observed 

 that in conjiua the vast majority show the dark quadrate and small 

 triangular marks by the stigmata. Immediately adjacent to the 

 conjiua are two rows oi festira from Sutherlandshire, one row consist- 

 ing of captured specimens, the other of bred, and in not a single 

 instance are these dark spots seen. Shetland eonflua appear, therefore, 

 to be geographically separated from the southern form of festira 

 having a parallel variation, by a race in which these dark spots are 

 wanting. Before leaving the general question of colour I would here 

 remark that the lower wings of conjiua are much darker than those of 

 festira. The larvae also of the two forms are very distinct, those of eonflua 

 keeping much darker even when bred in the south for two generations. 

 If, at the time when I was breeding both species, I had had the slightest 

 notion that I should have ever been asked to write a paper on the 

 subject I should have made careful notes and observations. 



Turning from the average colours to the relative shapes and sizes 

 of the two forms, it will be readily seen that here again we have 

 equally well marked characters, the fore-wings of festira being more 

 broadly triangular and proportionately wider near the hind margin 

 than in eonflua, less acute at the apex, and more rounded on the hind 

 margin. The average size of conjiua is distinctly smaller than that of 

 festira. 



One or other of the general characteristics just depicted may be 

 found to break down when comparing single specimens, but I maintain 

 that a consensus of these characteristics affords a sufficient guide to 

 enable one without difficulty to arrive at a satisfactory determination. 



It will now be seen why I consider the confusion that has arisen 

 respecting these two forms to be due to the inclusion undta- the name 

 eonflua of certain small forms from Scotland and Teesdale. Such 

 forms are largely represented in both Mr. Tutt's and my own series, 

 but they will be found not to conform either in colour or shape to the 

 Shetland specimens. 



I will now direct your attention more closely to my own series, 



