2l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I37 



(b) completely or almost completely in the inflorescences for the 

 heteromorphic, apterous or subapterous forms constituting the great 

 majority (most of the Agaoninae and Idarninae). 



The females belonging to group (a) present no modifications, but 

 a more or less exceptional development of the terebra, and also some- 

 times, in connection with this development and therefore with the 

 oviposition, peculiar deformations of the last abdominal segments or 

 other regions of the gaster. 



The females belonging to group (b) show more or less greatly 

 complicated modifications of several regions of the body and also of 

 the segmental and tegumental appendages. Of such modifications 

 some are common to all the members representing the taxonomic 

 groups under consideration, others are characteristic of particular 

 genera or species. However, both appear related to the work which 

 females have to do to penetrate into the inflorescences. Nevertheless, 

 some of them are unnecessary, except such as are likely to aid the 

 female during her efforts. (We remember, for instance, the flattening, 

 disintegration, and consequent deformability of the head capsule ; the 

 peculiar conformation of the first three joints of the antennae and the 

 recurved bristles, which are often found on the 2d toothlike antenno- 

 mere, the formation of a new organ, namely, the particular mandibular 

 process having the shape of a broad transversely carinate, serrate 

 appendage, the localization of series or complexes of small recurved 

 odontoid processes in various regions and appendages of the body, the 

 strengthening of the fore and hind legs, the shortening of their tibiae 

 and their rich outfit of spiniform or odontoid bristles, the transforma- 

 tion of the maxillary stipites into sclerotized plates horizontally ar- 

 ranged so as to form a kind of chisel, and so on.) Others seem to be 

 the result of involution or rudimentation of organs or appendages 

 (atrophy of the labrum, more or less advanced reduction of the maxil- 

 lae with atrophy or disappearance of the maxillary palpi, a more or less 

 advanced rudimentation of the labium and disappearance of the labial 

 palpi, reduction in number or disappearance of ocelli, a more or less 

 advanced reduction of the distal parts of the fore-wing venulation, 

 etc.) ; others do not seem to have, at least in our opinion, any particu- 

 lar functional meaning (a more or less pronounced and sometimes 

 hypertelic elongation of the head capsule, orientation in subvertical 

 direction of the mandibles, their transformation into strong, rather 

 complicated organs, the formation of enormous, monstrous new organs 

 such as the fore tibial laminae in the genus Sycoecus Waterst., in 



