26 Mr. J. O. Westwood on the ChalcididcB 



at Coomb Wood in Surry, in the month of July or August, on an old 

 rail made of a bough from which a part of the bark had been stripped. 

 The sexes were in equal profusion, and they were all running about upon 

 the barked part of the rail, where the sunbeams fell with great heat; 

 when disturbed, they flew to another part of the rail without leaving it. 

 Might they not have been watching for some internal or sub-cortical 

 feeding larva in which to deposit their eggs ? I also beat another speci- 

 men of the female from, I believe, an oak, at the latter end of August, 

 near Ensham in Oxfordshire. Mr. Cooper's males were taken the latter 

 end of July, on the trunk of a decayed elm, near Knight's Hill Cottage, 

 Dulwich, and Mr. Stephens's was taken, in June last, at Ripley in Surry. 

 Fabricius, in his Systema Piezatorum (p. 152, 16.) describes this 

 species as follows : " D. nigra, aeneo-nitens, abdominis basi pedibusque 

 ferrugineis; alis albis, maculis duabus marginalibus, atris ;" and Latreille, 

 (who in his Histoire Naturelle places this species in his division of Cynips, 

 of which he says, that the abdomen is " presque rond dans les males,") 

 thus describes it, " Vert bronze ; antennes, base de I'abdomen et pattes 

 " d'un fauve pale; deux taches noiratres sur les ailes superieures. Com- 

 " mune aux environs de Paris sur les ormes." 



These descriptions, I need not state, are specifically applicable to 

 Mr. Curtis's male maculipennis, and the original detailed description 

 of quadrum in the Entomologia Systematica (Vol. II. p. 186) is evidently 

 drawn from a small dark-coloured specimen of the same sex, notwith- 

 standing the expression of Fabricius in that description, " Abdomen — 

 aculeo brevi exserto." The mention of this aculeus was doubtless the 

 cause which induced Mr. Curtis to suppose that the description of 

 Fabricius was drawn from a female, and that, as his specimens- were 

 males, they would not agree with the description of the Fabrician species, 

 and were therefore to be considered as a new species. Had Mr. Curtis, 

 however, more accurately examined the abdomens of his male specimens, 

 he would have perceived that they possessed a short, exserted ayideus, 

 as Fabricius has misnamed it, and which is, in fact, the tip of the male 

 organs of generation,* the structure of which I have exhibited in Figures 



* De Geer has fallen into a precisely similar error. In describing the abdo- 

 men of the male of Eulophus pectinicornis he has observed, " Au postfirieur 



