Vol. XXVl] ENTOMOLOGICAL NEWS. 213 



taxonomically, and, in fact, appears to have been overlooked by 

 Reuter and previous authors as noted by Bergroth (1. c.), who 

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

 and in certain Restheniini several longitudinal veins may be 

 present. 



The veins of the metathoracic wing were named by Fieber 19 

 as shown in fig. 5. Reuter 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 subtensa. This structure is considered 

 by Reuter to be of importance in tracing phylogenetic relation- 

 ships, its presence indicating a relatively primitive condition. 

 It is absent in Adelphocoris, 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 Plagiognathus, 

 which belongs to the Phylinae, a more primitive group. 



CONCLUSION. 



The main anatomical features on which is based the classifi- 

 cation of the Miridae may be summarized as follows: The 

 form and structure of the arolia; the presence 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 

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

 other characters of lesser import, used in defining the lower 

 groups, may be mentioned the structure of the xyphus; 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 characters were discovered by 

 various 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 Reuter. Color and 

 markings are for the most part very variable within specific 

 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. 



19 Eu. Hem. 1861, p. 13. 



