288 SOUTIT-AFRICAX EUTTERFLIES. 



Pyrgus Diotnus, Mtischl., Verh. Zool. • Eot. Gesellscli. ^Vien, 1883, p. 



286. 

 Hesj>ena Sandastcr, Stand., Exot. Schmett., ii. pi. 100 (1888).^ 



Bxp. ciL, I ill. — I in. 2 lin. 



Aspect of P. Vindex, Cram., hut not of so deep a black, with the 

 spots of a duller v:hlte and mostly rather narrotver ; cilia yellowish- 

 white, with the black mtemqytions duller and not so sharply defined. 

 Fore-wing : basi-costal wliitisli more diffused, not forming a distinct 

 white mark inwardly ; cellular spots narrower, the inner one occa- 

 sionally wanting ; in disced row there is no seiKirate fourth spot, that 

 marking being immediately and vertically beneatli, and completely united 

 with third sjwt. Ifind-iving : basi-cellular spot usually small and 

 indistinct, and sometimes wanting ; median band narrower, duller, 

 and more oblique than in Vindex, crossed rather conspicuously by end 

 of black median nervure and origins of its second and third nervules, 

 and often narrowly and indistinctly prolonged towards costa. Under 

 SIDE. — Hind-wing and apical area of fore-wing pede greyish or yelloivish- 

 ochreous, tisucdly with a slight greenisli tinge in $ ; hind-iving with sid)- 

 bascd and median white strii^cs very oblique, well separated — the former 

 rather vaguely defined internally and inferiorly, — the latter with well- 

 defined edges (not much denticulated), continuous, and varying little 

 in width from costa to where it joins anal-angular white ; white spots 

 of submargincd roiu confluent into an irregularly-denticulate rather ill- 

 defined, streak, also obliquely placed and -running almost parallel with 

 median band ; beyond this streak, the hind-marginal border is much 

 paler than the rest of the ground, and often nearly white in $. Cilia 

 beneath rather indistinctly interrupted with greyish-ochreous, espe- 

 cially in hind-wing. 



A fine $ example taken in Basutoland by Colonel Bowker varies 

 in possessing much enlarged discal spots in the fore-wings. 



This species is readily recognised by the peculiarly oblique white 

 bands on the under side of the hind-wings ; and Herr Moschler (Joe. 

 cit.) was undoubtedly right in dissenting from my suggestion in 1866 

 that it was proljably a variety of Vindex; but I had as long ago as 

 1870 (Trans. Ent. Soc. Lond., p. 385) corrected that suggestion, and 

 stated that I had seen reason to hold Diomus as distinct. 



About Cape Town this butterfly is numerous ; its habits are precisely those 

 of P. Vindex, and the two forms fly in company. Tliongh having an exten- 

 sive range in the Southern Tropical Kegion, Diomus does not appear to have 

 been recorded from any locality north of the Equator. Its distribution in 

 South Africa proper seems to be general, but it has appeared more rarely than 

 Vi7idex ill collections received. 



^ Dr. Standinger's figure has no resemblance to P. Sandastcr, Trim, (see below, p. 291), 

 but represents an apparent ? of P. Diomus. 



