Affinities of Cheiropachus Quadrum. 27 



R, S, T, and U, and the description of which will be found in the Ex- 

 planation of the Plate. 



Spinola has united this species in his Insecta Liguriae (Vol. II. p. 208) 

 with his species varians and pallipes, the former of which is formed, 

 with others, into a section of his genus Halticoptera, in the Annales, the 

 quadrum being entirely omitted in the latter work, which species does 

 not indeed agree with the loosely drawn characters of that genus. 



Latreille has omitted quadrum in his Genera Crustaceorum, and 

 Dalman has placed it as the first species in the first section of his very 

 extensive genus (or rather subfamily) Pteromalus. 



The observations which Mr. Curtis has made upon the affinities of 

 Cleonymus being founded upon the characters of the male of Cheir. qua- 

 drum, may with propriety be inserted here, since it is now evident 

 that they are not applicable to Cleonymus, but belong to the present 

 genus. He says, " The trophi of Cleonymus are so very similar to those 

 " of Colax, that we should not have established the latter genus had not 

 '* other characters presented themselves; it is true that the mandibles of 

 " the former are stronger and have but two distinct teeth, and the 

 " terminal joint of the maxillary palpi is shorter and more dilated; but 

 " on comparing the males of the two genera more decided characters 

 " will be found to distinguish them, and such as we trust will justify 

 " their separation. The males of Colax are marked by a very large head, 

 " a ring-shaped proiliorax, an obovate abdomen and slender thighs; the 

 " same sex of Cleonymus, has a moderately sized head, a bilobed prO' 

 " thorax, an obconic and thick abdomen, and robust anterior and in- 

 " crassated posterior thighs." 



The characters which separate the females of Cheiropachus from those 

 of Colax, although not so striking as those existing between the other 

 sex, are sufficient to warrant the separation of the two groups. The chief 

 are the incrassation of the anterior thighs in Cheiropachus, and the dif- 

 ference of the formation of the collar and abdomen ; the latter of which 

 in this genus, it will be seen, is not longer than in the females of Colax, 



du ventre on voit une petite partie pointue en forme d'aiguillon, qui sans con- 

 tredit est la tarriere que I'lchneumon introduit dans la feuille habitee par une 

 chenille pour y deposer un ceuf." Vol. I. p. 590. 



