164 BRITISH BUTTERFLIES. 



Another is described by Nickerl thus : — 



(d) The left half with the colouring of the ? , the right with that of the i . A 

 bluish stripe extends from the base of the left hindwing towards the hind-margin, so 

 .that the wing is divided into two brown patches, the lower of which has also the 

 appearance of being powdered with some bluish scales near the inner margin of the 

 wing (Lep.-Fn. Bulim., p. 19 ; translated by Muller, Ent. Mo. Mag., iii.. p. 114). 



We note one in Plebeius lycidas as follows :— 



Right side of typical c? coloration, left side ? . The underside shows no variation 

 of ground colour or spots, in fact it is more symmetrical in this respect than many 

 specimens otherwise normal, but there are more blue scales at the bases of the wings 

 on the J side than on the other. The body has not been critically examined but can 

 be seen to be asymmetrical at the apex. The example is in perfect condition and was 

 taken above the 2nd Refuge, on the Simplon Road, July 14th, 1908 (Prideaux). 



The actual range of species in this genus has not been determined. 

 The species that appear to fall here are : — " In Europe : P. argus, L., P* 

 argyrognomon, Bergs., P. lycidas, Trapp, P. zephyr us, Friv. ; in Asia : 

 P. cleobis, Brem., P. tancrei, Graes., P. eversmanni, Staud., P. lucifera 

 (themis), Staud., P. eurypilus, Fit., P. pylaon, Fisch., /'. loewii, Zell., 

 P. allardii, Obth., P.fergana, Staud., P. martini, Allard, P.staudingeri, 

 Chrph., P. christophi, Staud., P. insularis, Leech, P. barine, Leech; in 

 N. America: P. melissa, Edw., P. aster, Edw., P. seudderii, Mosch. 

 (perhaps a variety of the preceding), P. acmon, Dbldy " (Wheeler). 



The group is widely distributed over the north temperate zone of 

 both hemispheres, extending, apparently, from well within the Arctic 

 circle to the southern verge of the PalaBarctic and Nearctic regions, 

 one species, Plebeius argyrognomon, in the Pala?arctic region, extending 

 from Algeria (36° N.' lat.') to Finmark (70° N. lat.), and Plebeius- 

 argus (aegon) also extending from northern Scandinavia to southern 

 Spain, Italy, Greece, Asia Minor, etc.,whilst in Asia both species occur 

 almost as far south as the Himalayas, and as far east as China, Corea, and 

 Japan, with P. argus reaching as far west as Ireland. In the NewWorld, 

 Scudder says (Butts. New hhigl., pp. 956-960) that, in the western half 

 of the Nearctic region, it extends into warmer regions than in eastern 

 North America, for, in all, it occurs between 40°N. lat. and 60°N. lat., a 

 region which represents a much colder climate in eastern than in 

 western North America, indeed, in California, it probably descends at 

 least to the thirty-fifth parallel. He adds that, " according to Koch, 

 it is also found in southern Australia, which would accord with its 

 distribution in the northern half of the Old World, or better, with that 

 of the species found in western North America," but one suspects that 

 Koch's record hardly refers to our restricted genus Plebeius. 



We have already noted (vol. ix., pp. 327-^8) the amazing numbers 

 of the males of Plebeius argyrognomon, that collect at the runnels and 

 pools of water on the pathways in the Alps of Europe ; P. a runs (aegon) 

 is sometimes only less abundant, again all males. Lintner records that 

 the allied P. seudderii has similar habits in North America. It collects, 

 he says, in large numbers on damp ground, and lie once counted 200 

 in one spot, and caught 15 with one sweep of the net. We have seen 

 /\ argyrognomon, so numerous that one might have put the net over 

 200 without difficulty, and have repeated the operation every ten 

 yards or so for above 1 a mile. 



Plebeius argus, Linne* (jegon, Schiff.) 



Synonymy.— Species: Argus, Linn., " Sys. Nat.," xtli ed., p. 483 (1758) ; 

 " Faun. Bueo.," 2nd ed., p. 288 (1761) ; ' (?) Pofla, "Mua. Gr»o.," p. 70 (17(H); 



