NEMATTJS BILINEATUS. 157 



which are not so darkly coloured on the upper surface ; 

 the cerci point outwards, while in ruficapillus the 

 contrary is the case; the spurs are longer and the 

 markings on the mesonotum form conspicuous marks 

 of distinction. 



Ab. a. Mesonotum with three nearly confluent 

 black marks, the vertex black in the middle, and the 

 stigma at base distinctly black. 



b. Mesonotum and stigma immaculate. 



Scotch specimens are smaller and darker than those 

 from the south, the aberration a being the common 

 northern form. The wings are deep black, almost 

 darker than in N. ruficapillus, the stigma also is deep 

 black at the base, and the metanotum is entirely black. 



The larva is very similar to that of N. ruficapillus, 

 and has the same habits and food plant. The head is 

 yellowish with two round brown spots on the vertex. 

 The eye-spots black and the mouth brown. The colour 

 of the body is grass-green throughout, and each seg- 

 ment has three transverse rows of white tubercles, each 

 ending in a white hair; these being found also on the 

 overhanging sides. In size it is slightly larger and 

 broader than the commoner species. 



The eggs are laid on the underside of the leaf along 

 the mid rib in two rows. The pupa state is passed in 

 the ground. In this country I believe there is but one 

 generation in the year, which occurs from August to 

 October. 



N. bilineatus is tolerably common, and generally 

 distributed. In Scotland I have taken it in Clydes- 

 dale, Strathglass, Glen Feshie, Eannoch, and Suther- 

 landshire. In England the only precise localities I 

 know of are York (F. G. Binnie) and Worcester 

 (Fletcher). 



Its continental distribution is extensive ; it is found 

 all over Scandinavia, in Finland to lat. 63, in the 

 Island of Solowetsch, in the White Sea (Palmen, teste 

 Zaddach), Livland, Curland, Germany, Holstein, 

 Silesia. 



