128 [Xovcmber, 



The larva) 1 found feeding on Salix cinerea in August, on the hills 

 between Port Grlasgow and Grreenock ; and I have got them feeding 

 on birch in Cadder Wilderness, Hannoch, and Kingussie, in June, 

 July, and August. They eat along the edge of the leaves in a similar 

 fashion to the larvae of ISf. melanoce'pJialus. The cocoon is double, and, 

 in confinement, was spun either in the earth or between the leaA'ea ; 

 the flies made their appearance in July, and from the late-feeding 

 brood in the following spring, there being evidently two broods in the 

 year. In some of the cocoons the outer covering is separated by a 

 considerable space from the inner one. 



Comparing this species with specimens of N. croceus, Fall. (= 

 fulvus, Htg.), taken in the same localities, it is seen that the antennae 

 in Cadderensis are shorter and thicker ; the abdomen is also shorter, 

 and at the same time broader and rounder : further, the cerci are 

 shorter, and the wings in croceus are much clearer, these in Cadder- 

 ensis having a decided yellowish tinge ; the clypeus in the latter species 

 is apparently deeper notched ; but all these are characters in which 

 both species tend to vary, and I am at a loss to point out distinctions 

 that will serve to discriminate the two species. We seem to have here 

 a case like in Lophjrus similis and L-i^ini, where two very differently 

 marked larva? produce very similar imagos ; and, in the present instance, 

 there is another interesting peculiarity, viz., the very great resemblance 

 which the larva of Cadderensis bears to that of N. melanocephahis, the 

 only apparent mark of distinction being, that in the former the orange 

 marks are nearly (if not quite) free from the black marks ; while in 

 the latter, these go through them in the middle. 



It is also worthy of remark that the imagos produced from the 

 willow-feeding larvae are smaller and darker coloured than those got 

 from birch, and the willow larvjc had besides a much brighter green 

 colour. 



I have submitted specimens of N. Cadderensis to Dr. van Yollen- 

 hoven and to Professor Zaddach ; the former gives as his opinion that 

 it cannot be distinguished from his iV. trimaculatus (Tijdschr. Ent. 

 Decl V, G9, pi. 4), while the Prussian naturalist is equally sure that 

 there is no way of separating it from JS'. croceus ; but the discovery of 

 the larva clearly shows that it is really a distinct species. 



AT. trimaculatus, Yoll., is I think only a var. of JSf. croceus. The 

 N. trimaculatus, Lep., is doubtless the gooseberry pest. 



With regard to AT. melanocephalus, it may be useful to give its 

 synonymy, as it has been involved in no little confusion. 



