INTRODUCTION. 



vein. These are the fourth, fifth, and sixth longitudinal veins. The 

 discoidal usually divides much. The postical vein is frequently 

 branched; a superior branch often unites it with the discoidal cell, 

 enclosing the posterior basal cell. This superior branch is the posterior 

 transverse vein. The anal vein runs simply to the margin of the 

 wing, sometimes unites again with the postical, enclosing an anal cell. 

 The third primary vein, when present, is the axillary vein. 



" The cells are named from the veins enclosing them. The medi- 

 astinal cell is between the mediastinal and costal veins ; the next cell 

 parallel to it, enclosed by the subcostal, is the costal cell; the sub- 

 costal is enclosed between the subcostal and radial veins ; and the 

 cubital cell between the cubital and radial veins, or, when the latter is 

 absent, the subcostal vein. The cell enclosed between the upper and 

 lower primary veins, and closed by the transverse vein, is the anterior 

 basal cell. The discoidal cell is situated on the disc of the wing 

 below the transverse vein ; it is enclosed by the discoidal and postical 

 veins and their branches, or by the former alone. The posterior 

 marginal cells occupy the posterior margin of the wing, and are 

 bounded by the branches of the lower primary vein, but the first and 

 most important of them is enclosed between the discoidal and cubital 

 veins, the transverse vein, and the margin of the wing." 



Loew. 



Costal vein 

 Axillary vein 

 1st longitudinal 

 2nd longitudinal 

 3rd longitudinal 

 4th longitudinal 

 5th longitudinal 

 6th longitudinal 

 7th longitudinal 

 Costal cell 

 Subcostal cell 

 Marginal cell 

 Submarginal cell 

 Basal cells 

 Discoidal cell 

 Posterior cells 

 Anal cell 

 Axillarv cell 



Schiner. 



Costal vein 

 Mediastinal vein . 

 Subcostal vein 

 Radial vein 

 Cubital vein 

 Discoidal vein 

 Postical A^ein 

 Anal vein 

 Axillary vein 

 Mediastinal cell 

 Costal cell 

 Subcostal cell 

 Cubital cell 

 Basal cells 

 Discoidal cell 

 Posterior marginal 

 Anal cell 

 Axillarv cell 



Macquart. 



Marginal nervure. 

 Mediastinal nervure. 



^Submarginal nei^vure. 



Externo-median . 

 Interno-median. 

 Anal nervure. 

 Axillary nervure. 

 Costal cell. 

 Mediastinal cell. 

 Marginal cell. 

 Submarginal cell. 

 Basal cells. 

 Discoidal cell. 

 Posterior cells. 

 Anal cell. 

 Axillarv cell. 



