114 



many taken at the same time, at the same spot, are nndoiibtedly A. 

 trifoUi; and we therefore have either the case of both species flying 

 together in one small locality (about half an acre), or that both 

 forms are A. trifoUi, or hybrid trifoliixhmicert/'. 



I do not know of any references to the genitalia of these two 

 species, and it would be interesting if any one here could say 

 whether these have been examined. 



Barrett, in " British Lepidoptera," states that he separated these 

 species in deference to generally accepted opinion, both here and on 

 the Continent ; but he doubts their specific distinctness, and 

 mentions that W. H. Fletcher has found them to interbreed 

 readily, and to produce offspring which remain fertile for many 

 generations. To add to the complexity, large specimens of A. 

 trifoUi, taken in numbers in July or early A.ugust, are termed 

 palustris by Oberthiir, and treated by Tutt as a sub-species. Again, 

 six-spot specimens of A. trifoUi have been taken, and A. trifoUi and 

 A. fiU'peuihila have been found paired quite a number of times. 



Before leaving these two species it may be of interest if I men- 

 tion some of the more important vars. of A. trifoUi which are 

 represented in this box. 



1. Firstly, the type is really a four-spot burnet, as the two 



central spots are coalesced. 



2. Ab. orobi is the true five-spot form, and occurs everywhere 



with the type. 



3. Confluent specimens are firstly ab. (/lycirr/iiz/f, with Nos. 3, 4 



and 5 spots more or less connected. 



4. Ab. basaUs is the reverse of this with spots 1, 2, 3 and 4 



connected. 



5. Ab. trivittata, all spots connected by threads of red. 



6. Ab. minoides, all spots confluent, forming a more or less 



regular red patch. 



7. Ab. interiiiedia, specimens tending towards yellow. 



8. The full yellow form, of which I have no specimens, is ab. 



h(tescens. 



I have a curious specimen from Pickett's Hole, with four minute 

 red spots on the left wing and five on the right wing. 



There is also a pair in cop., which I have never separated, taken 

 at Aubengues. These are large insects, the female, otherwise 

 typical A. trifoUi, is four-spotted, and the male is ab. orobi. 



I might mention that in some years, for example last year, quite 

 half the specimens of A. trifoUi taken at Pickett's Hole were of the 



