A FORTNIGHT IN THE FENS. 



By G. T. Porritt, F.L.S. 

 ( Concluded.) 



It is needless to particularise each day's doings separately, as we 

 spent them very much alike. From the second morning, however, 

 we generally beat over the thatched sheds and stables in the daytime 

 on our way to the fen, and in this way secured several species we 

 might otherwise have missed. Perhaps the best species taken was 

 the very local Aylossa cuprealis. I think we were as much pleased 

 with this moth as with any we took on our excursion, as it was totally 

 unexpected, and indeed I did not know any locality where it was 

 taken. The first two were found by Mr. Daltry in spiders' webs, on 

 July 24th, and were of course dead ; fine living ones were found 

 afterwards, but never more than one or two in a day, though these 

 were in different spots miles apart. One of them very obligingly 

 deposited a few eggs, which hatched in due course, and I hope I have 

 the larvae now feeding. No doubt the species would be found 

 generally distributed in Cambridgeshire if well looked for. 



As was natural amongst so much moss-covered thatch, the Scoparia 

 were in great force, though this was more in numbers than variety. 

 The best was lineolalis, but it was not common ; cembroe also occurred 

 occasionally, but mercuralis was in profusion ; on the sides of two 

 sheds in particular this species might have been taken almost every 

 day in scores. They varied very much in size and colour, some being 

 small and dull, others, females particularly, being large, dark, and 

 every marking clearly and distinctly defined. 



On the fen in the daytime, in addition to the species mentioned 

 previously, we were very pleased to find the larvae of Papilio Machaon 

 in tolerable plenty. We were evidently rather too late to see the 

 imago on the wing, though it must have been out a considerable 

 time, as the larvse were of every stage of growth. The very small 

 ones were insignificant-looking things, being dingy black, with pale 

 patch on the back, but the larger ones were gorgeous creatures. 

 They were generally easily found, their intensely bright green and 

 black, with red spots, shewing most conspicuously, especially as they 

 were usually on the upper side of the higher leaves of the wild carrot. 

 Even when not seen directly, their habit of feeding at once betrayed 

 their presence, as they strip off every vestige of leaf down one side of 

 the plant, leaving the bare midribs, whilst the leaves on the other 



N. S., Vol. IV., Ape., 1879. 



