A HISTORY OF NORFOLK other soil in these islands, yet in the district now under notice are often abundant. Such are Agrophila sulphuralis, Acidalia ruhricata, 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 Heigham, Merton, Thet- Bure, Tare and other rivers. This fine ^^> Aldeby ; very uncertain ; common species, which is very extensively dis- in the years 1868 and 1900 tributed over the globe, is in this Thecla betulas, Linn. Found at Sail 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 difBcult — 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 phlaeas, Linn. Common. Pieris crataegi, 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
