PLEBEIUS ARGUS. 205 



k. t . — Pale yellow in ground colour. Exhibited at the meeting of the Sth. 

 Lond. Entora. Soc, held on April 14th, 1887 (Briggs). 



\.-fj.. Two 2 s. — Of a very light brown tint. Captured Dover, 1887 (Webb, Ent., 

 xxi., p. 133 ; Barrett, Brit. Lep., i., p. 76). 



v. ? . — Ground colour above ochreous-yellow, shot with shiny grey; the orange 

 also, and the whole underside very pale, as if much faded, with the same silky 

 glaze as the upperside. A kind of albino from Sarepta (Xolcken, Lep. Fn. Estl., 



£. s . — The outer third of the fnrewing, and four-fifths of the hindwing with 

 the blue colour transformed to a rather dead but lustrous grey colour. Berisal, 

 July 3rd, 1906 (Prideaux coll.). 



o. <? . — The usual blue tint entirely replaced by a faint but lustrous mauve- 

 pink ; all the wing3 appear to be rather thinly-scaled and diaphanous. Berisal, 

 July 17th, 1908 (Prideaux coll.). 



Teratological, examples. — One suspects that teratological examples 

 are not so rare as the records might lead one to suppose. We have 

 noted: — 



a. 2 . — Right hindwing about two-thirds the natural size, short and broad, 

 the black spots before the orange series reduced to three medial and three post- 

 medial spots. Ventnor, August, 1883 (Hampson, Ent. Mo. Mag,, xxxvii., p. 120). 



/3. <? . — The right pair of wings normal and well developed, left pair, both 

 fore- and hindwing shorter and narrower than the corresponding one on the right, 

 presenting a marked difference in size. Lavin, August 9th, 1908 (Tutt collj. 



y. $ . — The wings all shortened, the forewings also broadened, the left fore- 

 wing more normal, the right forewing rounded on the outer margin ; the hind- 

 wings narrowed, the apex pointed, and the outer margin straight between the apex 

 and the anal angle. Captured at Simplon, July 1899 (Tutt coll.). 



8. c? • — The right forewing hollowed out on the inner margin ; the right hind- 

 wing shortened and narrowed, so that the wing is much smaller than the corres- 

 ponding left wing. Captured at Cuxton, June 29th, 1896 (Tutt coll.). 



e. s . — Right side both wings normal in shape and size ; on the left side the 

 hindwing slightly narrower than the right, and the left forewing, though uninjured, 

 is much reduced in size, and presents a shrivelled appearance, but the discoidal 

 spot is in its right proportional place (as compared with the right wing); the whole 

 wing is, however, narrowed to a short strap, with a slightly concave outer margin. 

 The dashes that are the equivalents of the marginal spots on the right wing are 

 absent on the left one. Captured at Berisal, June 29th, 1906 (Prideaux) = ab. 

 cuneata (antea p. 186). 



{. <? . — The tarsus divided into three joints instead of all the joints and terminal 

 claw being fused together without trace of articulation. Spain (Chapman, Proc. 

 Ent. Soc. Lond., 1909). 



Genitalic variation. — The ends of the clasps of Plebeius argus and 

 P. argyrognomon are very different ; the former with a few long teeth 

 rather on the side of the hard process (see antea p. 155), the latter 

 with a number of very fine teeth on the rather broad end of the 

 process. But the comb-like end of the clasp of P. art/its presents a 

 great (and most unusual) range of variation, the total number of 

 teeth varying within considerable limits, and the presence or absence 

 of one or several minor or ill-developed teeth at either end of the 

 series, is another point in which there is great inequality in different 

 specimens. We find even the opposite clasps of one individual 

 differing very frequently, and a different number of teeth to the comb 

 may be found in specimens from one locality (Chapman). 



Comparison of the malks of Plebeius argus and P. argyrog- 

 nomon*. — The confusion of the names of these species has lasted 

 considerably over a century, and we are now, 134 years later, using 



* Comparison largely made between specimens captured on the same ground 

 near Simplon village, August 4th, 1899 (see Ent. Rec, xii., pp. 38-39). 



