GLOSSARY. XV 



Hcterodactyla. The second of the two divisions into which Bratier divides his 



PLATYGENYA, which latter is the first division of his ORTIIOUEIIAPIIA 



BKACHYCERA. 

 Holoptic. Used of the head when the eyes are contiguous ; opposed to 



dichoptic. Generally a character of the male sex only, but exceptions 



occur in several families. 

 Hoinoeodactyla.Qne, of the two divisions into which Brauer divides his 



PLATYGENYA. See Hcterodactyla. 

 Hovering. This term expresses the habit of some flies of remaining quite 



stationary in the air, then suddenly darting away a short distance and 



again remaining stationary. 

 Humerus. The shoulder or anterior corner of the thoracic dorsum ; when it 



takes the form of a more or less distinct bump it is known as the 



humeral callus. 



Hypoccra. The name given to a superfamily consisting only of the PIIORID.E. 

 Hypopleura. The pleural area between the metapleura and the hind coxa. 

 Hypopygium. The male genital apparatus as a whole, as distinct from that of 



the female. 



Imagined disks. Centres of the formative tissue in the lame of certain insects 

 especially Diptera, which give rise to the legs, wings, etc. 



Intercalary veins (Loew). The lower prongs of the upper and lower branches 

 respectively of the 4th longitudinal vein (p. 12). The term has been 

 used by subsequent authors for various veins, but without obtaining 

 general acceptance. 



Johnston's organ. A minute structure in the 2nd antennal joint of Diptera 

 whiuh is supposed to contain the auditory nerves. 



Labella. A pair of organs, generally more or less oval or rounded, nearly 

 always at the tip (occasionally at the middle) of the proboscis. 



Lalrium. The lower lip. In Diptera always the lowest part of the proboscis, 

 and constructed, in the most highly developed forms, more or less like 

 a groove or case in which the remaining parts can be folded and covered 

 by the labrum. 



Labrum. The upper lip, the uppermost part of the proboscis in Diptera. 



Lamella, lamella. SinM leaf-shaped extremities to the ovipositor in the 

 female. A general term also for an oval or leaf-shaped flattened 

 terminal or projecting process. 



Lamella basalts supei-a and lamella basalts in/era,. Westhoff's names for the 

 upper and lower sides respectively of the 8th abdominal segment. He 

 terms the upper and lower sides of the 9th segment (namely, those 

 actually forming the genitalia) lamella terminally supera and infera, but 

 the terms have not been adopted by other authors. 



Macrocheetee. The large strong bristles in Diptera distributed over various 

 parts of the body, which are constant and possess a very high taxonomic 

 value. The study of this subject is termed Chatotaxy. 



Marginal cell. \ 



. , f See pp. 8 and 13. 

 Mediastmal cell. \ * v 



