52 LEPIDOPTEROUS FAUNA OF PORTLAND. 



think that the weakness of flight which I thought characterised it 

 might have something to do with its very limited distribution in 

 this country ; but this is evidently a mistake, and it must be 

 controlled by other causes. 



As regards the British species of this genus, one A. circellata 

 is confined to the neighbourhood of Manchester. The only record 

 of the larvae that I can find (E. M. M. iii. 90, iv. 132), merely states 

 that they were hatched from eggs laid by a captive female, and 

 were fed on knot grass. This, however, does not throw much 

 light upon the reason why it is so local. 



A second species, A. immorata, which has recently been 

 discovered near Lewes, is entirely confined to that neighbourhood, 

 so far as this country is concerned. It does not appear to be rare 

 in the place where it occurs, and it seems strange that such a large 

 insect should not have been noticed before. If, however, it is a 

 recent introduction, it is not unlikely that it may extend its 

 range gradually, if the neighbouring country is suitable to its 

 wants. 



Perhaps the next most local species is A. rusticata, which occurs 

 at Portland, but only in a few spots and not abundantly. It also 

 occurs more commonly in the neighbourhood of Darenth Wood, 

 Kent ; but I am not aware of any other British locality. The 

 larva feeds on hawthorn, and will also eat ivy, lilac, and bramble. 

 I do not see much difference between the Portland and Darenth 

 Wood specimens. I have met with this species both by day and 

 night at Portland, and do not consider its flight particularly weak. 

 The other more local species are ochrata, rubricafa, contiguaria, 

 holosericata, and striyilata, especially the last. The other 17 are 

 more generally distributed, five or six only being distinctly common. 

 From this we see that it is the habit of the genus to produce local 

 spcci.-s, and though, to take an instance, Darenth Wood apparently 

 resembles hundreds of places in England far more than it resembles 

 tli-- part of Portland wlu-re rusticata occurs, I suppose that there 

 must be some conditions specially favourable to this species in each 

 of these places. Probably there is some constitutional quality in 



