Vol. XXvi] ENTOMOLOGICAL NEWS. 213 



taxr r illy, and, in fact, appears to have been overlooked by 

 kcL previous authors as noted by Bergroth (1. c). who 



calls it an anal vein. Sometimes the membrane is ione-celled, 

 and in certain Restheniini several longitudinal veins may be 

 present. 



The veins of the metathoracic wing were named by Fieber'* 

 as shown in fig. 5. Router uses the same names, substituting 

 the word "vena" for costa in each case. In certain groups a 

 short and incomplete vein, the hamus, projects backward into 

 the cell from the costa subtcnsa. This structure is considered 

 by Rcutcr to be of importance in tracing phylogenetic relation- 

 ships, its presence indicating a relatively primitive condition. 

 It is absent in Adelpkocoris, which belongs to the Capsini. a 

 highly specialized tribe of the subfamily Mirinae, but in the 

 figure I have indicated its position as it occurs in PlagiognathuSt 

 which belongs to the Phylinae, a more primitive group. 



COKCLUSION. 



The main anatomical features on which is based the dassifi- 

 cation of the .Miridae may be summarised as folfews: The 

 fonn and structure of the arolia; the p resen c e or absence of 

 the apical stricture of the pronotum ; the structure of the lorae ; 

 the presence or absence of a wing-hamus ; the venation of the 

 mcnilirane, and the extent of the genae. Among the many 

 other characters of lesser import, tiscd in defining the lower 

 groups, may be mentioned the structure of the xyphtis; the 

 form and proportions of the antennal segments: the shape of 

 the head, prothorax. and parts of the hemelytra ; and the posi- 

 tion of the hind coxae. These diafacters were discovered by 

 x-arious authors, but the determination of their relative import- 

 ance and their employment in a coherent and comprehensive 

 system are in great measure the work of Renter. Color and 

 markings are for the most part very variable within speci6c 

 limits, and this, together with the fact that certain structures 

 also exhibit intra-specific variability, indicates that there is in 

 this family an opportunity for work on incipient species and 

 varieties which will be of general biological interest 



'* Ea. Hem. itfi, p. 13. 



