March, igiS.] KnIGHT: SyNOPTIC Key TO AflRID.E. 41 



used In- later workers. Renter found that the structures of the 

 aroHa, corresponding to the pulvilliE between the tarsal claws of flies, 

 in their modifications showed fundamental relationships between the 

 species and groups within the family. 



The present writer has spent much time studying and making 

 drawings of claws and arolia in all the genera obtainable from North 

 America and in this way is able to present a graphic record of the 

 characters used in the classification with the hope that the same may 

 make the keys more usable. Mr. Van Duzee has recently published 

 (Univ. Calif. Pub., Vol. i : 199-216, 1916) practical keys to the 

 genera of MiridcC but has not made much use of the subfamily group- 

 ing. 



Dr. W. E. Britton has kindly given his approval to the publica- 

 tion of the present key in advance of the work on Connecticut 

 Hemiptera and it is hoped by so doing, other workers may test it out 

 and suggest improvements. 



Key to the Subfamilies of Mirid.s:. 



1 . Arolia present ^ 



Arolia absent (sometimes two parallel bristles simulating arolia, figs. 



47-49) 8 



2. Arolia arising distant at the base (fig. 42) or upon the inner angle of the 



claw (fig. 14) ; or pseudo-arolia connate upon the inner curve of the 



claw (figs, i-i 3 ) 3 



Arolia always arising approximate at the base between the claws (figs. 

 15-36, 50-55), not connate with them but sometimes minute pseudo- 

 arolia are also apparent on the inner curve of the claw (figs. 27-29, 

 53-55) ; free, more or less linear, converging or diverging at the 



apices 



3. Prothorax simple, without an annuliform apical stricture 4 



Prothorax with an annuliform apical stricture, sometimes obsolete above 



in the middle 5 



4. Lorse distinctly separated from the genre ; ultimate segment of the tarsi 



linear, tibiae generally spinose Phylinae. 



Lorse confluent with the genae ; ultimate tarsal segment incrassate (fig. 

 43), rarely linear, tibiae destitute of spines Bryocorinae. 



5. Lorx linear, distinctly separated from the genae ; ultimate tarsal segment 



linear, tibiae finely spinulose Dicyphinae. 



Lorae confluent with the genae ; ultimate tarsal segment incrassate. tibiie 

 destitute of spines Bryocorinae. 



6. Arolia converging at their apices (figs. 15-36) Orthotylinae. 



Arolia diverging at their apices (figs. 37, 38, 50-55) 7 



