28 VARIETIES OP 



seem to be generally known how exceedingly pale the Continental 

 specimens of obelisca are in their palest forms, leading up to the var. 

 Jiastifera, Donz. of mountainous districts, which is of a distinctly 

 vinous-black coloration. It is because this insect is, compared with its 

 congeners, rare in Britain, that one is unable to express the same cer- 

 tainty with regard to it. My own series numbers less than thirty 

 undoubted British specimens, a number altogether inadequate to give 

 any idea of its extent of variation. The Continental forms help one, 

 however, to get a better idea of its affinities. Mr. Percy Russ has 

 captured in Sligo some fine forms of cursoria bearing a great superficial 

 resemblance to var. villiersii, Hb., but undoubtedly distinct from that 

 variety and to be referred to cursoria, thus giving another instance of 

 parallel variation in these allied species. The specimens which we 

 obtain from the South of Scotland are indistinguishable from speci- 

 mens of var. hastifera which I have from various German localities, 

 but some of these are very close to dark vars. of tritici, although a 

 well-trained eye readily distinguishes between them. There is another 

 variety, var. ruris, about which there is a great deal of difficulty in 

 my mind. Some specimens of this variety, which came through a 

 well-known lepidopterist (Mr. Dobree) into my hands, from Dr. 

 Staudinger, are altogether unlike all my previous thought of what 

 obelisca ought to be, and altogether unlike the type of ruris, Hb., fig. 

 416, which is a streaked form. They appear to be identical, however, 

 with Guenee's ruris. They are like some of my specimens of tritici 

 which I called cursoria-like, i.e., they are without the pale costa, with- 

 out the pale longitudinal markings ; in fact, they bring us back to 

 the root of the matter again, viz., that tritici and obelisca have cursoria- 

 like forms, whilst cursoria has the streaked tritici-like forms, and that 

 these varieties run in their extreme forms into each other so much, 

 that it is only by training the eye specially, that any real difference 

 is to be detected between any one of the species and the allied 

 ones, for the members of the whole group are so closely interwoven 

 one with the other, that it is most difficult to tell where one ends and 

 the other begins. 



I firmly believe, and consider it impossible of contradiction which 

 can be proved, that aquilina is a pretty generally distributed variety of 

 tritici which has never become localized, and which freely interbreeds 

 with typical tritici, and is therefore altogether, on any ground what- 

 ever, unentitled to rank as a species. I also consider that cursoria is 

 an extreme development of tritici, which has become specially modified 

 and constant within certain limits, that the specimens breed inter se, 

 and form a distinct species. It appears to be what Dr. Staudinger 

 would call a Darwinian species. 1 look upon obelisca, however, as a still 

 more highly specialised form, and consider that its constancy in 

 Britain may be either a proof of its more complete development, or, 

 owing to its greater rarity, a proof of our ignorance in not knowing 

 the different forms of variation through which it may extend. 



Agrotis, Och., obelisca, Hb. 



The type of this species is Hiibner's fig. 123, which may be 

 described as follows : " Anterior wings of a deep dull red coloration, 

 with ochreous costa, dark hind margin and typical stigmata. The 



