136 HYMENOPTERA. 



of these groups. I have therefore not adopted any divisions of lower than sub- 

 family rank. 



Subfam. ICHNETJMONIDM 



This subfamily has been divided into four subgroups by the Belgian entomologist 

 Wesmael* — into the Ichneumonides Oxypygi, the Ichneumonides Amblypygi, the 

 Ichneumonides Platyuri, and the Ichneumonides Pneustici. So far as I am aware no 

 representative of the last group has been discovered in our range. The other 

 three are represented ; but I have come to the conclusion that there is no absolute 

 distinction between them, the characters on which they are founded merging into each 

 other completely. And it is equally difficult to find characters to distinguish the 

 genera Ichneumon, Hoplismenus, Amblyteles, and Trogus. We find great variation in 

 all the parts of the body on which these genera have been based — in the antennae, the 

 head, the thorax and its scutellum, and the abdomen. There are, for example, all grada- 

 tions from a flat scutellum up to one which is strongly dentiform and spinose. Cresson 

 (Proc. Acad. Phil. 1873, p. 105) has come to the same conclusion, that it is impossible 

 to define clearly a Hoplismenus from an Ichneumon (sensu str.). The genus Ichneumon^ 

 as here used, is practically equivalent to the Ichneumonides Oxypygi, and Ichneumonides 

 Amblypygi, of European writers. 



PATKOCLUS. 



Patroclus, Cresson, Proc. Acad. Phil. 1873, p. 104. 



Cresson regards this as a subgenus of Ichneumon (as above defined) ; but the pecti- 

 nate claws furnish such a good mark of distinction that it seems to me, especially 

 seeing the difficulty there is experienced in differentiating Ichneumon, that it may well 

 be raised to generic rank 



— • l. Patroclus nigrocaeruleus. (Tab. VII. fig. l, $ .) 



Ichneumon (Patroclus) nigrocaruleus, Cresson, Proc. Acad. Phil. 1873, p. 104 \ 



Eab. Mexico, Orizaba 1 ; Guatemala, Zapote, Las Mercedes 3000 feet, summit of 

 Volcan de Agua 12,400 feet (Champion). 



~~ 2. Patroclus lectus. 



Ichneumon lectus, Cresson, Trans. Am. Ent. Soc. ii. p. 18 [<J & ? ] \ 

 Eab. Mexico, Orizaba 1 . 



- — 3. Patroclus toltecus. 



Ichneumon toltecus, Cresson, Trans. Am. Ent. Soc. ii. p. 17 [<y & $] \ 

 Hah Mexico, Orizaba \ 



* Tent. Disposit. Method. Ichneumon. Belgii, p. 11. 



