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NORTH A:\IERICAN DIPTERA 



GLOSSARY OF TERMS USED IN DIPTEROLOGY 



Abdomen — The hindermost of the three main body divisions. 



Acalypteratse — The Acalypterate Muscoidea — those with very small or linear 



squamae. 

 Acrostical bristles — The rows of mesonotal bristles between the dorsocentrals — 



the two median rows of bristles of the thorax. 

 Acrostical hairs — Hairs lying between the dorsocentral bristles. 

 Acrostical setulse — Very shoi't hairs between the dorsocentral bristles. 

 Adventitious veins — Veins occuiring in abnormal positions, sometimes rather 



regularly placed, and sometimes normally present, 

 ^deagus — Part of the male negitalia: the penis and its sheath. 

 Alate — Having wings. 

 Alula — A lobe at the base of the wing posteriorly. 



Ceria. Ceriomydas. Conops. 



Examples of mimetic resemblances in flies. 



Anal cell — The cell lying between the fifth and sixth veins (Cu). 



Anal crossvein — The crossvein closing the anal cell apically — (Cui.) of Com- 



stock-Needham. 

 Anal lobe — The basal part of the wing behind the anal vein. 

 Anal vein — The sixth longitudinal vein. The second anal is usually absent 



or represented by a fold. 

 Anepisternite — The mesopleura. 



Annulate — Having rings, but not completely segmented. 

 Annulus — A ring or band. 

 Antennae — The feelers, attached to the head and separating the face and the 



front. They are sensory organs and perhaps combine the senses of smell 



and hearing. 

 Antennal fovea — See antenna! grooves. 

 Antennal grooves — Definite depressions in the middle of the face in which the 



antennae may rest. They are limited laterally by the facial ridges and in 



the middle, unless they are united, by a carina. 

 Anterior crossvein — The short crossvein connecting the third and fourth longi- 

 tudinal veins on the basal half of the wing — (r-m). 



