THE ENTOMOLOGIST. 



No. 140.J MARCH, MDCCCLXXV. [Peice 6cl. 



Life-histories of Bawflies. Translated from the Dutch of 

 Dr. S. C. Snellen van Vollenhoven by J. W. May, Esq. 



(Continued from p. 28.) 



Nematus abbreviatus, Hart. 



Imago : Hartig, Blatt-und-Holzwespen, p. 205, No. 38. 



Larva hitherto undescribed. 



Nematus fusco-niger, crassus, abdomine contracto, prothorace 

 supra, trochanteribus, femorum apice, tibiis tarsisque 

 anterioribus luteis, tibiis tarsisque posticis variegatis. 



The genus Nematus of Jurine, which was, in fact, first 

 precisely defined by Hartig, is, like all the divisions of the 

 last-named author, made to depend principally on characters 

 derived from the course of the nervures of the wings, and the 

 genus so defined contains groups differing considerably in 

 the structure of the body : some are slender, and more or 

 less attenuated; and to this group belong N. Salicis and 

 N. septentrionalis, and similar species, the larvae of which have 

 twenty legs, seldom, however, making any use of the last 

 pair, and have the habit of almost incessantly alternately 

 raising and depressing the abdomen. Others, to which our 

 species Abbreviatus belongs, are short and compressed in 

 form, and apparently proceed from larvae having only eighteen 

 legs. If this obtained as a rule, which I am far from being 

 able to assert, it would, I think, tend to prove that divisions, 

 depending exclusively on differences in neuration, are artifi- 

 cial and not natural ; it would, however, be rash to attach 

 too much weight to an observation made upon the metamor- 

 phosis of a single species. 



VOL. VIII. H 



