224 Forty-fourth Report on the State Museum 



male example of G. viminalis in the Cambridge collection. If 

 the male should show the peculiar structure ascribed to Cladius 

 in its diagnosis as given by Cresson, viz., "basal joints of flagellum 

 produced or branched beneath " (as appears conspicuously in our 

 Cladius isomera Harris), then A. lutescens is assuredly distinct, for no 

 approach to such structure is presented in its antennae. 



Mr. Jack has pointed out a discrepancy in the description and 

 figure of Cladius given by Cameron, in that the former calls for four 

 submarginal cells, while his figures of the male show but three. 

 This, however, is but of little importance, since the nervulation in 

 the Tenthredinidce is known to vary to so great extent that it seems 

 hardly to afford a sufficient basis for separating genera. Aulacomerus 

 is one of the several genera which are based on comparatively slight 

 differences in venation. The family certainly needs a thorough study 

 and revision with the aid of a knowledge of the European species, 

 with which a number of ours, will in all probability prove identical. 



I have not been able to compare the life-history of C. viminalis with 

 that of A. lutescens, but the following note of the European species 

 has just come under observation: 



In M. le Dr. Jacobs' " Tenthredines, Cephides & Siricides des Envi- 

 rons de Bruxelles," contained in Comptes-Bendus des Seances de la 

 Societe Entomologique de Belgique, 1884, xvi-xxiv, is this (p. xix) : 



Trichiocampus* viminalis Fallen. The larva lives in August and Sep- 

 tember, on the willow and poplar, of which it eats the under side of 

 the leaves; the perfect insect appears in June. 



Compared with the above, and essentially differing — A. lutescens 

 larva feeds in June and August, resting on the upper side of the leaf 

 and consuming all but the stronger ribs; the perfect insect appears 

 at about the middle of July. 



Note. — Just as the above is being printed, the identity of Aulaco- 

 merus lutescens with Cladius viminalis of Europe, has been determined 

 by Mr. Peter Cameron, of Sale, Cheshire, England — an authority in 

 European Tenthredinidse . Examples of our species, in both sexes, 

 were submitted to him, and he has returned answer that they are cer- 

 tainly C. viminalis. He also states that A ulacomerus has nothing to do 

 with Cladius so far as can be made out from the description and rough 

 figure. Mr. Cameron has also kindly sent colored figures of the 

 European larvae, which agree with ours. 



* A genus of Hartig, separated from Cladius of Illiger. 



