553 



HYMENOPTERA 



is very different to what it was previously. It changes to 

 a pupa inside the case of the Trichopteron in a cocoon attached 

 to the walls of the case. Previous to making this, however, the 

 Agriotypus forms a curious, elongate, string-like process attached 

 to the anterior extremity of its cocoon. The use of this is 

 unknown. Full information as to the life-history of this aquatic 

 Hymenopterous larva, especially as to its respiratory functions, 



B 



FIG. 365. Metamorphosis of Agriotypus. (After Klapalek. ) A, Larva ; B, sub-nymph ; 

 C, case of the Silo with the string of attachment formed by Agriotypus ; D, section 

 of the case : v 1 , operculum of case ; 2 , cocoon ; ag, pupa of Agriotypus ; e, exuvia 

 of Agriotypus ; 'w~, wall of cocoon ; s, remains of Silo ; iv l , closure of case. 



would be of great interest. The affinities of this remarkable 

 Insect are still doubtful. It may probably prove to be between 

 Proctotrypidae and Ichneumonidae. 



Eemains of Insects that may be referred with more or less 

 certainty to Ichneumonidae have been found in some abundance 

 in various tertiary strata both in Europe and North America, but 

 nothing indicative of the existence of the family has yet been 

 found in the older rocks. 



Fam. V. Braconidae Supplementary Ichneumon-flies. 



Antennae with many (nearly always more than fifteen} joints, not 

 geniculate. Wings with a moderate number of cells, which 

 on the anal part of the front wing are more or less imper- 

 fect, the anal (i.e. the second posterior) cell being separated 

 from the cubital cells by a large space in which there is no 

 cross-nervure. Abdomen with but little mobility between the 

 segments ; the suture between the second and third usually 



