GLOSSARY. 



Acalyptrata. — One of the two great subdivisions of the Muscid.e, comprising 

 those species in which the squamae are of equal size or nearly so, 

 or absent. They embrace twenty or more groups which are taxo- 

 nomically subfamilies only, but on account of their magnitude are 

 by some authors regarded as families. See Calyptrata. 



Acephala or acephalous larvre. — Those in which there is no differentiated 

 head ; as opposed to the Eucepiiala. 



Acetabulum. — The minute joint attaching the coxa to the body. 



Acroptera. — Brauer's third division of the Orthorrhapiia Brachycera, con- 

 sisting only of the LoNCiiorTEEiD.E. Considered by him a super- 

 family. 



Aculetis. — A term used in Hymenoptera to denote the sting of such insects as 

 bees and wasps, but since no Diptera are aculeate, the term has been 

 employed by certain of the older authors to define part of the genital 

 organs. See Style. 



Adminiculum. — WesthofF's name for the variously structured guard of the 

 penis in Tipulid.e. 



Aerial dancing. — Applied to the habit of many species of Diptera and other 

 orders of foriuiug small clusters in the air, usually beneath the lower 

 boughs of trees or over streams, and Hying mainly up and down with 

 considerable swiftness. This habit is somewhat different from that 

 known as "hovering" {q. y.), and, at least as regards Diptera, seems 

 to be chiefly confined to the males ; mox-eover, they appear most addicted 

 to the practice towards sunset. 



Alula. — The anal lobe of the wing proper, and not to be confounded with the 

 squamffi, or tegula;. Many authors (including myself in my earlier 

 notes) have erroneously used the term to denote the squamte (p. 15). 



Ambient vein. — The very fine vein running round the hind margin of the wing 

 from the end of the costa to the base. 



Am2)hipneustic. — Larvas with spiracles on the first and last segments only. 



Anal cell.— The cell behind or posterior to the oth longitudinal vein when that 

 is present (p. 14). 



Anal vein. —The 6th longitudinal vein, having theoretically in front of it the 



anal cell, and posterior to it the axillary cell. 

 Antennal grooves ov fovew. — A longitudinal groove or pair of grooves in the 

 middle of the frons, for the reception of the antennae, bounded on each 

 side by the facial ridge. 

 Anterior legs.— The four frout legs taken together, the first pair only being 

 termed the fore or front legs. 



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