106 ENTOMOLOGICAL NEWS. [May, 



The work evidently took years of patient labor and research, 

 and it has been too long neglected by European and American 

 writers on these insects, as it contains excellent tables and hints 

 and ideas on the classification of this difficult group, which, it 

 worked out thoroughly, would undoubtedly aid materially in ad- 

 vancing a systematic knowledge of these insects. In separating 

 the Ichneumons into so many families and genera, Forster prob- 

 ably went to the extreme, and this may account for the little value 

 placed on the work by his contemporaries, but from the little 

 study I have as yet given to his work, I am fully convinced that 

 many of his so-called families will hold good, with some modifi- 

 cation, as Tribes, in the sense of LeConte and Horn. 



His family 2oth, or the Mesochoroidae for instance, will form a 

 natural tribe, Mesochorini, in the subfamily Ophioninae, distin- 

 guished by the large, rhomboidal areolet, and by the two promi- 

 nent projecting anal styles in the males. 



I have been led to these views by a somewhat careful study 

 of some of the families characterized in his work, and by the 

 discovery of two remarkable male insects that for a long time 

 baffled me in placing one in the National Museum and the other 

 in my own collection but which I find, with the aid of Forster' s 

 tables, belong to two new genera briefly characterized in his work. 



In describing these two insects I have deemed it advisable to 

 give below not only a table of the genera of this tribe, but a full 

 generic description of these two imperfectly known genera, so 

 that other students may easily recognize them. 



Tribe MESOCHORINI. 

 Table of Genera. 



Vertex narrowed, lateral ocelli close to the margin of the eye ; claws 



pectinate G. i. Plesiophthalmus Forster. 



Vertex not narrowed, lateral ocelli distant from the margin of the eye. 

 Claws pectinate; first abdominal segment with lateral carinae extending 

 backward from the spiracles; transverse median nervure in hind 

 wing broken . . . . G. 2. Astiphromma Forster. 



Claws simple; first abdominal segment without lateral carina?; trans- 

 verse median nervure in hind wing not broken. 



G. 3. Mesochorus Grav. 



Plesiophthalmus Forster. Head transverse, not wider than the thorax 

 across the wings, antero-posteriorly thin; the frons foveated; clypeus not 

 separated; ocelli large, prominent, the laterals close to the eye margin; 



