GLOSSARY. XVII 



guished by a distinct ring, ridge, or well defined space, or not. The 



frontal orbit is that part of the orbit immediately abutting on the frons. 

 thocera. Schiner's and Brauer's name for the BOMBYLIJIORPHA, PROCEPIIALA, 



and POLYTOMA. Schiiier, however, includes LEPTID.E in the OKTIIOCERA. 

 Orthogenya. Brauer's second division of his OUTIIORKIIAPIIA BRACIIYCEKA, 



composed only of EMPID.E and DOLICHOPID.E. 

 Ovate. Egg-shaped, that is, an ellipse more pointed at one end than the 



other. 



Opposition. The act of depositing eggs by the female. 

 Ovipositor. The female genital organs, as distinguished from those of the 



male. 



Palpi, palptu. These organs in the Diptera possess from one to five segments; 

 the vast majority of Brachycerous flies having only one segment, and 

 the NEJIATOCERA four. In many groups they are rudimentary, in 

 others absent (p. 19). 



Pectinate. When the vestiture of the antenna; is stronger than stiff pubescence 

 or verticillate hairs and takes the form of stiff bristles, or branched 

 pendulous or variously formed solid projections, they are termed 

 pectinate. 



Pectus. The breast. Walker used it to denote the lower anterior part of the 

 thorax. Modern authors do not, I believe, employ the term. 



Peripneustic. Larva; with spiracles on the median segments, as well as at the 

 head- and tail-end^, are so called. 



Peristoma, or peristome. Apparently a synonym of epistoma. 



Piceous. Blackish brown ; pitch colour. 



Pile. A very closely set and very short pubescence of erect hairs resembling 

 the " pile " of velvet. 



Platygcnya. Brauer's first division of the OKTIIORKIIAPIIA BRACHYCERA, com- 

 prising all the families except the EMPID.E, DOLICIIOPID.E, and LOXCHOP- 

 TERID.E. 



Pleura. The sides of the thorax are in many Diptera separated into fairly 

 distinct divisions by two sutures running longitudinally to the axis of 

 the body, and by one perpendicular or transverse suture. The upper 

 suture is the dorsoplcural (or more correctly notopleural) ; the lower 

 longitudinal suture is the sternopleural. The vertical suture (though it 

 is seldom either straight or absolutely vertical) is the rnesoplcural. The 

 pleurae (or spaces) are named the propleura (or prothorax), mesopleitra, 

 and pterovleura, the two latter divided from each other by the meso- 

 thoracic siiture. Below the sternopleural suture are, the ftemopleura (in 

 front) and the hypoplcura (above the middle and hind coxae). The meta- 

 pleiira is a more or less indistinct space behind the pteropleura and 

 hypopleura, and adjacent to the metanotum. 



Plumbeous. Leaden colour, which may be dull or shining. 



Poitiers, or balancers. The older authors' terms for the halteres. 



Pollinose. An expression used to define a surface with a light dust-like 

 covering, resembling pollen ; a finer vestiture even than tomentum. 



Polytoma. Brauer's (and Bezzi's) name for a superfamily consisting of the 

 TIIEREVID.E and SCENOPINID.E. 



