SEASONAL POLYMORPHISM. 177 



donzelii, July-August. Brenthis palen var. arsilache, July-August, at 

 Statzer Lake. 



Tarasp. — Lycaena amanda, mid July-August (in rushes). Erebia 

 medusa var. hippomednsa, May-June. PobjommatHs iiwiccKjer, June, 

 near Kurhaus. 



Tessin. — Gonepteryx cleopatra, April-May and August. ( 'hryso- 

 phanii^i alciphron var. yordius, June-July. 



Trafoi on Stelvio. — Chrysophanus alcipJiron var. yordius, always 

 there. Lycaena auianda, June-August. Polyoinuiatus donzelii. June- 

 August. 



Upper Engadine. — Krebia yorye ab. triopes. 



Val Muranza (extreme E. centre of Suisse). — Erebia nerine var. 

 stelviana, July-August, on rocky slopes. 



Wassenstein (Albula Pass, near top). — Colias palaeno ab. ? 

 werdandi, mid June- July. 



Zernetz. — Erebia nerine var. stelviana (3 miles above Zernetz). 



Kaces and Seasonal Polymorphism of the Grypocera and of the 

 Rhopalocera of Peninsular Italy. 



By ROGER VERITY, M.D.. and ORAZIO QUERCI. 



(Conlinued from page 158.) 



If one gives a comprehensive glance to those species which have a 

 comparatively limited area of distribution and to the broader groups of 

 races of those which are widespread, one distinctly detects the 

 existence of several European zones characterised by their Lepidoptera ; 

 it must, of course, be understood they usually blend into each other in 

 transitional regions, because here, as in most cases, natura non facit 

 saltuni. I will briefly attempt to draw a sketch of these zones, so as to 

 establish the position of the one we are dealing with. I leave out 

 Russia, which still needs being worked out more thoroughly. The 

 examples I quote are all drawn from the Grypocera and from the 

 Ehopalocera, but it must be borne in mind that the Heterocera afford a 

 considerably greater number and amply confirm the same conclusions. 



I. Arctic zone, including Northern Scandinavia and Finland : 

 Characterised by its very limited number of species, by never produc- 

 ing more than one generation yearly, by several peculiar species and 

 races, only resembling the Alpine ones of very high altitudes. 



II. Zone of Northern Europe, as far south as Central England and 

 Central Scandinavia : Characterised by two generations of the trigene- 

 rate species, the second being, however, often very partial ; no peculiar 

 species ; races transitional between preceding and following. 



III. Zone of Northern Central Europe, including the South of 

 England and of Scandinavia, the extreme North of France, Belgium, 

 Holland, Denmark, and the extreme north of Germany : Two genera- 

 tions constantly produced, and a third in favourable years in a few tri- 

 generates ; species distinctly more numerous than in zone II ; races 

 distinctly northern, usually small, frail, and pale, in those species 

 which do not spread further north thah this zone, but distinctly more 

 robust and brighter than in preceding zones in the species which do 

 reach them ; a marked feature is the greater individual variability and 

 the tendency to produce more extensive dark markings, in many species, 



