1886.] 171 



on working the Typha latifolia in the very place where I took canntc 

 on the wing, I found that I invariably got pupae of ti/ph(B and nothing 

 else. Accordingly, I had quite made up my mind that there must be 

 some mistake as to the food plant, and am the more glad to be able to 

 confirm Treitschke's account. 



In ordinary seasons the locality is inaccessible except by water, 

 and the nature of the soil (a floating or " dancing " bog) makes it 

 impossible to get to any distance inland. This year, however, the ex- 

 treme dryness of the fens rendered it practicable with high boots, and 

 a couple of boards for help at the worst places, to get almost anywhere, 

 and I determined to avail myself of the opportunity. Devoting alto- 

 gether about four days to the task, I searched, as thoroughly as possible, 

 all the fen round my favourite locality, as well as some promising beds 

 of Typha elsewhere ; the result was a large number of pupse of iV. 

 fyphcB, and a very few of can7i(B. The latter I found very easily dis- 

 tinguishable, the larva being greenish instead of putty-coloured, while 

 the pupa is not only decidedly smaller than that of typhce, but is also 

 furnished with a very prominent and conspicuous beak containing the 

 palpi. The distinction given by Treitschke, though usually correct, and 

 in fact the best rough test, is not absolutely reliable, for I obtained one 

 Cannes with its head down, and four or five fyph^ with their heads up. 

 I I suppose that the latter would all have perished, having their backs 

 to their entrance holes ; indeed, two of mine did so, after which I 

 opened the others to give them exit. As the two species of larvae are 

 feeding in precisely similar places, it follows, of course, that the hole of 

 canncB, above the larva, is much higher up the plant than that of 

 typhc^, which is below ; in fact, it is usually quite up in the leafy part 

 of the Typha, and very inconspicuous. 



The pup^e of ca7incv were all found in the heart of the fen at some 

 distance from the river, a few in small detached plants of Typha 

 latifolia, the greater part in the dense reed-beds, where it was difficult 

 to force one's way. These beds had evidently not been cut for years, 

 and were a perfect miniature jungle, affording magnificent shelter to 

 other creatures besides insects, while they contained here and there 

 considerable quantities of Typha latifolia and anyustifolia, Cladium 

 mariscus, &c. All these plants I searched as well as I could, being by 

 no means satisfied with the take of canned from T latifolia. Ihe 

 smaller species of Typha produced several ^ typhce, hut no cannc. ; 

 still it is much harder to work than the larger plant, growing m dense 

 masses and being liable to turn brown naturally, thus depriving one of 

 ^r« the surest indication of the presence of a larva, so that 1 may very 



