VARIATION OF CERTAIN AGROTID.i:. 175 



occurs ; most lepidopteiists have a generally correct idea of what 

 (iqtiilma ought to be ; a few, however, do not seem even to 

 understand these elementary necessities. The continental lepi- 

 dopterists long ago understood this question, and Hiibner's 

 figure 135 takes its true position in their lists, as the type of 

 tritici var. aquilina, his figures 535 and 53(3 being referred to 

 other varietal forms. 



With regard to the old British authors they have had a 

 comparatively easy task. Every new form of tritici which 

 occurred was described as a new species and named as such ; the 

 forms represented by the type-names are difiicult to trace, but 

 Wood's, and Humphrey & Westwood's publications have figures 

 of most of these varieties. 



The variation of tritici is so extreme, that it is almost im- 

 possible to give any idea of it. Without egotism, I may safely 

 assert, that I have one of the finest series of this species at 

 present in existence. Some 500 to 600 specimens, picked from 

 perhaps twenty or thirty times that number of specimens, 

 include some of the most magnificent forms that can be imagined. 

 The ground colour varies from pale whitish grey to intense black, 

 but with all this variation there is one thing that immediately 

 strikes a student when a classification or grouping is attempted, 

 viz., that all these moths can be divided into two groups — 

 (1) those that have no distinct pale longitudinal markings (costal 

 streak, nervures, &c.), but have very complete transverse mark- 

 ings (as in typical cursoria) ; and (2) those that have distinct pale 

 longitudinal markings, with the transverse ones broken up. I have 

 divided my specimens upon this plan, into four distinct sections 

 according to ground colour, m^., grey, slate, brown and black, and 

 these again are distinctly graduated according to the depth of these 

 various ground colours. I place forms with the same ground 

 colour in following rows — (I) with the transverse markings and not 

 the longitudinal ; (2) specimens with the same ground colour as 

 the previous row but with longitudinal markings. Nearl}' three 

 drawers of picked Agrotis arranged in this way makes material 

 for careful study and carries conviction with it. I want now 

 specially to refer to those forms of tritici which are without 

 longitudinal markings. These specimens, whitish grey, slate- 

 colour, yellowish ochreous, brown, reddish brown, intense black, 

 with every intermediate colour, have every line, every mark the 



