Zoology 69 



the fauna is still a remarkable one. Perhaps the best way to give the reader 

 a brief introduction to it is to consider rather the different types of 

 habitat exhibited by the coimtry near Cambridge than to attempt any 

 description of the different species. 



First, Cambridge itself deserves mention, since its old walls are the haunt 

 of a special race of a moth {Bryophila muralis), of wliich the typical form is 

 largely confined to the southern and western coasts. The species has never 

 established itself in the adjacent villages (even when introduced) but, in 

 Cambridge town, it seems able to survive the changes of modern times. 

 The moth appears in August and the larvae feed on the algal growth on 

 old walls, like those of its common relative, B. perla. 



Leaving Cambridge, the most important habitat is that of the Fenland. 

 Most of this area is intensively cultivated, but fen species persist in the 

 dykes and clay pits; instances are the local "Wainscot" moths, Lencania 

 ohsoleta, Senta maritima and Notiagria arundinata, found where the common 

 reed is left uncut, and the marsh carpet (Cidaria sagittata), a rare and local 

 species occurring in dykes (also fens) where its food plant — meadow rue — 

 grows. A few areas remain in a more primitive condition, the fens of 

 Wicken and Chippenham in Cambridgeshire being the most famous. 

 Wicken, best known for the swallow-tail butterfly, is also the haunt of 

 many interesting species, such as the reed leopard {Macrogaster castaneae) 

 and the marsh moth {Hydrilla palustris), the latter a very rare insect with 

 the habit of flying cliiefly between midnight and dawn. The Dutch large 

 copper butterfly, very closely resembling the extinct English large copper' 

 is being re-established at Wicken.' Chippenham somewhat resembles 

 Wicken in its Lepidoptera, but the swallow-tail is not found there, 

 although some other species occur more abundantly — as, for instance, the 

 Noctuid Batikia argentula, elsewhere in the British Isles almost confined to 

 Killamey. 



The higher land immediately bordering the Fenland, and also the higher 

 parts of the Isle of Ely, support three characteristic Tortricid moths 

 (Phtheochroa schreibersiana, Pammene trauniana, Laspeyresia leguminam) and, 

 in addition, one of the scarcest of British " dagger " moths {Acronycta strigosa), 

 which elsewhere has only been found near Tewkesbury, a remarkable dis- 

 tribution in view of the universal occurrence of hawthorn, its food plant. 



Next to the Fenland, the most important area is that of the Chalk in the 



' See p. 188 below. 



* Woodwalton Fen, not far from the site of the former Whittlesea Mere, in 

 Huntingdonshire, contains some of the fen species found at Wicken, and also 

 another local Noctuid Tapitiostola extrema, at one time thought to be extinct. This fen 

 is best known for the successful re-establishment of the Dutch large copper butterfly 

 a race very closely resembling the extinct Enghsh large copper. 



