INTRODUCTION. 



XXV 



crystallized into a permanent shape ; second, because nearly 

 all the existing literature has the nomenclature here employed 

 and to use a new one would largely defeat the object of the 

 work in the hands of the beginner. I give below the ter- 

 minology used by Comstock, together with the equivalent 

 terms here used and the equivalent ones in the terminology 

 of Schiner, for the horse-fly. 



Auxiliary vein .... II 



First longitudinal .... III1 



Second longitudinal . . . 1112,3 



Third longitudinal .... III5 



Fourth longitudinal . . . V2 



Fifth longitudinal V3 



Sixth longitudinal .... IX 



Anterior branch of third vein . III4 



Anterior intercalary . . . V2 



Posterior intercalary . . . VIII 



Costal cell 2ndl 



Subcostal cell II 



Marginal cell III1 



First submarginal cell . . . III3 



Second submarginal cell . . III4 



First basal cell .... 2ndIII 



Second basal cell .... V 



Anal cell . . . . . VIII 



Axillary cell IX 



First posterior cell .... III5 



Second posterior cell ... VI 



Third posterior cell . . . 2ndV2 



Fourth posterior cell V3 



Fifth posterior cell .... VIII 



Discal cell lstV2 



Mediastinal 



Subcostal 



Radial 



Cubital 



Discoidal 



Postical 



Anal 



Costal 

 Mediastinal 

 Subcostal 

 Cubital 



Flies differ very much in the nature of their covering. 

 Many are nearly or quite bare; others have a thick, woolly 

 covering of closely set, long fine hair ; while others still have 

 an abundant covering of long stout, heavy bristles or[macro- 

 chcet(K. Undoubtedly the kind of covering has much relation 



