200 University of California Puhlications. [Entomology 



in most of the Phylaria, is apparently always absent in the 

 Orthotylini where it seems to have been discarded, but in the 

 Oncotylaria, which is intermediate between these groups, it may 

 be either present or absent in the same genus, possibly in the same 

 species or individual. 



The characters of the arolia present a similar case. Their 

 form seems to be constant for each tribe but in any, at least of 

 the larger ones, it may be entirely absent in certain genera. I 

 would not, however, consider the arolia a vestigial character as 

 is the hamus in the wing-cell. 



In these keys I have attempted to arrange the tribes and 

 genera in what seems to me to be the correct descending order, 

 but here there certainly is a large field for investigation and 

 many changes will probably have to be made. The claspers, or 

 genital hooks, of the male form excellent specific characters in 

 many cases, but there are groups of species here and there in 

 which these hooks exhibit scarcely any appreciable differences 

 between what are undoubtedly good species. 



The following are the eight genera omitted from the keys : 

 Neocapsus Dist., Pallacocoris Reut., Neoborops Uhler, Eccrito- 

 tarsiis Stal, Teleorhinus Uhler, Cyllocoris Halm, Ortlwcephalus 

 Fieb., Microsynamma Fieb. 



As a matter of convenience the following terms are explained 

 here. 



Arolia. — The pulvillae between the base of the tarsal claws, sometimes 

 free, sometimes united with the claws beneath. 



Bucculae. — A narrow plate lying either side of the base of the rostrum; 

 rarely used in the Capsidae. 



Callosities.— A more or less elevated area on either side of the anterior 

 lobe of the pronotum, usually distinguished by an impressed bound- 

 ing line, at least posteriorly. 



CheeJcs or gena. — The two sclerites below the eyes and between the 

 clypeus and gula. Between them is frequently a narrow segment 

 called the lora. The inner or upper cheeks may be nearly flat or at 

 times considerably elevated or tumid. 



Clavus. — The inner area of the elytra next to the scutellum and separ 

 ated from the corium by the claval suture. It is usually long- 

 triangular in form, with its apex near the base of the membrane. 



Clypeus or tylus. — The median lobe of the head below the front and 

 reaching to the base of the rostrum. 



Collar or collum. — The narrow anterior margin of the pronotum. Gen- 

 erally separated from the disk of the pronotum by an impressed 

 line which may or may not be continued over the side. 



