92 BRITISH BUTTERFLIES. 



of an obsolete outer marginal orange line towards the anal angle 

 of the hindwing are also observable in some specimens. Reverdin 

 mentions (in litt.), a $ , taken near Geneva, with pure white fringes 

 to all the wings, and a small tawny line, 5mm. in length, well- 

 marked, just above the fringes, towards the anal angle of the hind- 

 wings. The fringes vary considerably from being almost uniform 

 with the ground colour to almost pure white, those of the hindwings, 

 as a rule, being lighter than those of the forewings. A very distinct 

 greenish tinge on the costal half of the hindwing is also occasionally 

 observable in some lights. On the underside, the tint of the green 

 varies considerably, that of some being much more brilliant than 

 others. Reuter notes two examples, one from Gamla Karleby and the 

 other from Russian Karelia as bluish-green = ab. caerulescens. There 

 is also sometimes a fairly well-developed narrow marginal edge to the 

 hindwings, orange in colour, which is occasionally continued upon the 

 forewings, and appears as a base to the fringes. The quantity of 

 white spotting on the underside of the wings varies greatly. Blachier 

 notes that, at Geneva, the following forms appear : 



1. Row of silvery spots well marked on all four wings (very rare). 



2. Row of silvery spots on the hindwings only (less rare). 



3. Only two silvery spots on the hindwings, one at the costa, the other towards 

 the middle of the wing (common in both sexes). 



4. Only a single point, viz., on the costa of the hindwings (not rare). 



This latter is, of course, the type form, so far as the spotting is 

 concerned, for Linne says in his description "hindwing beneath green, 

 a white spot near the upper margin." Blachier says that he has 

 never taken the true caecas at Geneva. The variation in the white 

 spotting appears to be quite independent of locality, some of the most, 

 and some of the least, marked specimens, in this direction, in our 

 cabinet coming from Carqueiranne. On the whole, however, we 

 should suppose the extreme forms in both directions to be rare. We 

 would distinguish the most marked forms as follows : 



1. — Well-developed rows of white spots on all four wings (usually three on 

 forewings and seven on hindwings) =ab. punctata, n.ab. 



2. — Well-developed row of white spots on hindwings only = ab. in feropunctata, 

 n.ab. 



3. — Incomplete row of white spots on hindwings = ab. incompleta, n. ab. 



4. — Two white spots only on hindwings, one at costa, one towards centre of 

 ordinary row = ab. bipunctata, n.ab. 



5. — One white spot only on hindwings, viz., at costa = rubi, Linne. 



6. — With no white spots on fore- or hindwings — ab. eaecus, Geoff. 



We are quite aware there are other intermediate forms not noticed here, 

 and we have one example in which the white spots form a continuous 

 line on the hindwings and almost so on the centre of forewings = ab. 

 connexa, n. ab. Stephens notes (Mux. Brit. Knt., i., p. 78) a var. p y 

 which he describes as having " the anterior wings with a row of 

 white dots beneath on the costa ; the posterior with a strong 

 continuous series, forming a streak." There are sometimes distinct 

 traces of a median discal white spot on the underside of both fore- and 

 hindwings. Chapman observes that, " in the Riviera, a large per- 

 centage of the specimens are almost eaecus, having only one spot on 

 the costa of the hindwing, and this seems to be really the type of the 

 Rivieran race." These examples are also usually of the intermedia form 

 in ground colour, and one obtains in southern France, etc., intermedia- 

 punctata, intermedia -inferopunctata, intermedia-incomplete Intermedia- 



