VARIATIONS OF THE VIPER IN GREAT BRITAIN. 87 



sharp frost last night froze the water in the buckets. A continual 

 mewing cry was heard over the lake, which was enveloped in a 

 thick mist — the cry of some duck, perhaps Wigeon. Passing a 

 Buzzard, more Wild Duck, and several Divers, we crossed the 

 arctic circle at Sillvjouk where there was once a silver mine. 

 We fished with success at the Seddvastrom, where an Osprey was 

 seen fishing. The second Fjallotuga was reached, and Sept. 2nd 

 gave us another half-walk, half-row, with fishing at mid-day, to 

 the third and last Swedish Fjallotuga. This was reached by 

 traversing several lakes and their connecting streams, and a 

 sinuous, sluggish river, where I saw some nets in which a young 

 Red-breasted Merganser, Mergus serrator, had been entangled. 

 Here we met some Norwegian bear-hunters ; they had not yet 

 found any traces of Bears, but had just seen a large Eagle. 

 Fresh snow had fallen on all the mountains round. 



Sept. 3rd. In the window at Merkenis were a great many 

 annuals growing — stocks, everlasting-flowers, and tomatoes. A 

 hard walk over the pass through a snow-storm was unproductive 

 of birds, except " Hyper," Wheatears, and a Greenshank ; and at 

 13.30 we crossed the boundary into Norway, eventually to 

 descend to the Salten Fiord en route for Bodo and England. 



AN INVESTIGATION INTO THE VAEIATIONS OF THE 



VIPER IN GREAT BRITAIN. 



By G. A. Boulenger. 



A few years ago* I drew the attention of the readers of 

 1 The Zoologist ' to the great amount of variation presented by 

 the Common Viper or Adder, Vipera berus, in the scaling of the 

 head. Characters which for many years had been almost 

 universally accepted as of sufficient importance for instituting a 

 distinct genus (Pelias) proved, on investigation of a large series of 

 specimens, to be inadequate even for specific diagnosis. The 

 subject, which had been discussed by Lataste and Tourne- 

 ville,f has since been more fully dealt with by Camerano, in his 

 Monograph of the Snakes of Italy,! who goes so far as to lower 



* ' Zoologist,' 1885, p. 373. 



f Bull. Soc. Zool. France, 1879, p. 132 ; and 1881, p. 38. 



} Mem. Accad. Torin. (2), xxxix., 1888. 



