70 DISTRIBUTION OF SPECIES. 



distributed. It has already been stated that some of our native 

 Lepidoptera are to be had in almost equal abundance in all 

 parts of the country alike, but there are several species whose 

 range is just as restricted. Thus one of the Skippers a group 

 intermediate between the typical Butterflies and the Moths is 

 confined almost exclusively to a spot on the Dorsetshire coast 

 known as Lulworth Cove ; although it there occurs in such 

 profusion, that Mr. Douglas once caught a hundred in about two 

 hours, frequently taking five or six in his net at one stroke. 

 But a far more curious case is that of a little Moth (Boletobia 

 fuliginaria) that from its colour deserves the name of the 

 chimney-sweep, and which has occurred in this country nowhere 

 but in the metropolis, the only recorded localities for it being, of 

 all places in the world, Blackfriars Bridge, Fleet Street, and a 

 coal-cellar at Chelsea ! 



Between this extreme of restriction in range and the almost 

 universal diffusion of our commoner species, there is every 

 possible variation. The beautiful Hawthorn Butterfly, or Black- 

 veiued White (Aporia cratcegi), is now one of oui most local 

 species ; but some years ago it appears to have been widely distri- 

 buted, and in the neighbourhood of London its caterpillars used 

 every spring to do great damage to the fruit trees. Occasionally 

 it happens that insects, which are usually accounted somewhat 

 rare, make their appearance in great profusion. The Clouded 

 Yellow already noticed is one of these ; so also is the great 

 Death's Head Hawk-Moth, which a few years since occurred in 

 such abundance, that the pupa: were turned up by the hundred 

 in potato-fields in all parts of the country. But a still more 

 remarkable instance is that of the Convolvulus Hawk-Moth 

 (Sphinx convolvuli), which, though almost unknown in the larva 

 state, and generally an insect of rare occurrence, has yet on two 

 or three recent occasions been taken in abundance all over the 

 country ; one specimen which fell in our own way, having been 

 found one morning comfortably settled on the knocker of a 

 street door in the classic region of Shoreditch ! 



The old collectors say that these seasons of profusion come 

 round periodically, and they point to the lovelv Painted Lady 

 (Cynthia cardui) as an insect which swarms in this way every 

 seventh year. Our own experience, however, would lead us to 

 doubt the truth of this assumption ; and, in so far as Cardui 



