A HISTORY OF NORFOLK 



other soil in these islands, yet in the district now under notice are often 

 abundant. Such are Agrophila sulphuralis, Acidalia rubricata, Lithostege 

 nivearia, Oxyptilus distans, 'Tinea imella, and more rarely Dianthecia 

 irregularis. 



A circumstance which must not be overlooked is the geographical 

 position of the county, and the great probability of its serving as a refuge 

 for insects driven by the occasional migratory impulse from the opposite 

 shores of the Netherlands, Denmark, the Baltic coast, or Scandinavia. 

 To such an impulse in themselves or in their progenitors may possibly be 

 ascribed the occurrence of such exceedingly rare species as Syrichthus 

 alveus, Notodonta torva, Noctua Jiammatra, Cloantha perspicillaris, Heliothis 

 scutosa and Ophiodes lunaris ; while to more successful immigrations may 

 be due the presence as residents of such species as Eupithecia extensaria, 

 Cateremna terebrella, Tortrix decretana, 'T. lafauryana. Coccyx ochsenheimeriana 

 and Bryotropha tetragonella ; possibly also some which we have been 

 accustomed to look upon as restricted to northern mountain districts — 

 Mixodia palustrana, M. rubiginosana and Cedestis gysselinella. 



There is work of abundant interest to be found also in the 

 extensive tracts of heath land, interspersed with bog and marsh, lying 

 between Sandringham and King's Lynn, with their apparently inexhaus- 

 tible riches in Micro-Lepidoptera ; also in the chalk districts around 

 Swaffham and elsewhere, or at Ringstead near Hunstanton, with their 

 casual or frequent production of the insects of the South Downs. In 

 the following list universally common species have not been enumer- 

 ated : — 



RHOPALOCERA 



Papilio machaon, Linn. In the fens of the vergate, Potter Helgham, Merton, Thet- 



Bure, Tare and other rivers. This fine /"''d-, Aldehy ; very uncertain ; common 



species, which is very extensively dis- in the years 1868 and 1 900 



tributed over the globe, is in this Thecla betulae, Linn. Found at 8all by the 

 country usually confined to two coun- Rev. T. H. Marsh, and also recorded 



ties, of which Norfolk is one. Here, by Curtis {British Entomology, p. 264) 



flying swiftly along the fen drains, and as found in Norfolk 



the banks of the slower rivers, or haunt- — w.-album, 111. Very local ; Newton St. 

 ing the beds of wild flowers in swampy Faiths, Lynn, Denton, Stoke Holycross 



spots, it is by no means uncommon, and — quercus, Linn. Local, upon the out- 

 its larva may often be found feeding upon skirts of woods and occasionally in the 

 the leaves of the milk parsley (Peuce- fens 



danum palustre). From the difl!icult — rubi, Linn. Norwich, St. Faiths Heaths, 

 or almost inaccessible nature of much Swannington, Stody, Merton, Thetford, 



of this ground there is good cause for Broome Heath, and commonly at Caw- 



hope that it will not readily be exter- ston 



minated in this county Chrysophanus phlasas, Linn. Common. 



Pieris cratagi, Linn. Formerly taken in the Varieties with pale clouding on the 



county ; but, as in most other parts of fore wings are not unfrequent on boggy 



England, now extinct heaths, and a form having the hind 



Colias edusa, Linn. Extremely irregular and wings wholly black, and the fore wings 



uncertain in its appearances, but at in- broadly bordered with the same colour, 



tervals widely spread in the county while the usual spots are nearly 



— hyale, Linn. Norwich, Lynn, Hal- obliterated, has been taken near Lynn 



138 



