POLYOMMATUS ICARUS. 145 



already (antea, p. 131) noted the form in which the dark dashes enter 

 into the basal half of the fringes in the $ . This is evidently the main 

 peculiarity of lacon, here described as a $ form, in which the character, 

 however, appears to be much rarer than in the other sex. 



7r. ab. thetis, Esp., "Eur. Schmett.," L, p. 332, pi. xxxii. (supp. viii.), fig. 2 

 (1777); [Prunn., " Lep. Ped.," p. 59 (1798)] ; Steff., "Bull. Soc. Ent. Ital.," xxxii., 

 p. 336(1900); Tutt, "Nat. Hist. Brit. Butte.," iii., p. 333 (1909). Oceanus, Bergstr., 

 "Nom.," iii., p. 9, pi. liii., figs. 3-4 (1779). Caerulea, Fuchs, " Stett. Ent. 

 Ztg.," xxxviii., p. 133 (1877); Buhl, "Pal. Gross-Schmett.," pp. 268, 761 

 (1893-5); Tutt, "Brit. Butts.," p. 176 (non 175) (1896); Grover, "Ent. Bee," ix., 

 p. 312 (1897); Favre, " Macr.-Lep. Val.," p. 19 (1899); Kroul., "Bev. Buss. Ent.," 

 iii., p. Ill (1903); \Yheeler, "Butts. Switz.," p. 35 (1903); Verity, "Bull. Soc. 

 Ent. Ital.," xxxvii., p. 28 (1905); Smallmn., "Ent. Bee," xix., p. 41 (1907); Gillm., 

 "Int. Ent. Zeits. Gub.," ii., pp. 1, 11 (1908); Grand, op. cit., ii., p. 79 (1908); 

 Trautm., op. cit., ii., p. 162 (1908); Seitz, "Gross-Schmett.," p. 312, pi. SOg, 

 (1909); Bebel, " Berge's Schmett.," 9th ed., p. 70 (1910). Coerulea, Auriv., 

 "Nord. Fjar.," p. 14(1888-1892); Beuter, " Macr. FinL," p. 13 (1893); "Ent. 

 Bee," v., p. 276 (1894); Kroul., " Soc. Ent.," vii., p. 172 (1893).— Alis caeruleis 

 margine nigricante obductis, fascia maculari utrinque fulva obsoletiori subtus 

 ocellis numerosis. This P. thetis appears to be very little distinguished from 

 medon, yet, in the case of living specimens, it strikes the eye at once as being 

 something different. The brilliant blue of this shading into brown (which no 

 art can reproduce) distinguishes it very strongly from medon. The % has 

 also been discovered and illustrated on pi. xxxiii., fig. 3. This at once deter- 

 mined it as a separate species. One often entirely fails to find medon in localities 

 where this is as common as possible. Its orange-coloured band consists of fewer 

 spots. The underside of the wings has several of them, they are in greater 

 numbers, have a narrower bordering and are placed in quite a different manner. 

 . The aberrations that I have met with are distinguished by the more or 

 less prominent blue on the upperside; but I have never had an entirely blue one, 

 such as von Bottemburg speaks of, come into my hands .... The 

 present P. thetis is met with in July with us, as well as later, but only rarely ; 

 much smaller examples sometimes occur (Esper). 



Borkhausen, in 1788, recognised (Sys. Besch., i., p. 161) this as a 

 form of P. icarus, and Esper's figure of thetis (pi. xxxii., fig. 2), which 

 his description shows he thought to be a ■ $ , is a well-known 2 form of 

 this species with orange antemarginal lunules on all the wings ; the 

 ground colour fuscous, the costal margin of both fore- and hindwings 

 dark, but the rest of the wings scaled with blue from the base to beyond 

 the discoidals, the blue just falling short of the orange lunules ; the 

 hindwings with the interneural marginal spots edged with blue. The 

 insect represented in pi. xxxiii., fig. 3, and referred to as the 2 , belonging 

 to this supposed g , is a 2 icarus without blue, but with orange 

 spots on the upperside of all the wings. Bergstrasser points out 

 (Nom,, iii., p. 9) that his oceanus (pi. liii., figs. 3-4) is identical 

 with Esper's thetis. He also remarks on the close alliance of 

 thetis, Esp. (oceanus, Bergstr.) with his pampholyge (another 2 form 

 of P. icarus, see antea, p. 141), as well as salacia and venilia [two 

 2 forms of Agriades thetis ( = bellargus) see preceding vol., p. 344], 

 the quantity of blue scaling leading him to question whether 

 thetis, Esp., might not be the $ of all these various forms, as 

 Esper had supposed, but this, of course, is not so ; it is merely one 

 of the many blue 2 forms of the common P. icarus. Fuchs' caerulea 

 is also referable to this form. He states that " the blue 2 aberration 

 of P. icarus is not very rare in the neighbourhood of Bornich, in both 

 the first and second broods, the first example having been captured 

 August 21st, 1875, whilst, at the end of May and beginning of June, 

 1876, he found blue 2 s in abundance." His description is identical 



