2 



INTEODTJCTION. 



The pupa is fixed or free; in the great division of the 

 OiiTKOERHAPliA it is muiiiniy-iike, that is to say, shewing more or 

 less in outlin(! the parts of the future imago, the shape of the 

 head, antennte, wings, and legs often being conspicuous ; in the 

 second great division, the Cyclokrhapha, it is long egg-shaped, 

 bearing no resemblance to the future insect, and exhibiting? no 

 parts w hatever of the body in outline. 



In the perfect state (imago) Diptera are to be found practically 

 everywhere and in every conceivable situation, a few species 

 occurring even in very high latitudes and desert areas. 



A general introduction to the whole order of the Diptera is not 

 contemplated in this volume, and the various parts of the insect 

 are sufficiently well known to the majority of entomologists not 

 to require more than a brief description. Tlie following ex- 

 planatory paragraphs on the external anatomy of a fly are there- 

 fore curtailed as far as expedient. The genus Tijmla is selected 

 as an example owang to its being the chief genus ol the TiPULiJ)iE, 

 the dominant family included in the present work. 



^ 



-Diagram oi' a Tipulu, to illustrate tlic parts of a Dipteroii. 



Head: — 



/'. Frons. 



V. Vertex. 



0. Occiput. 



p. Tip of palpus. 



w. Neck. 

 Thorax : — 



c. OoUare or prothorax. 

 m.s'. Mesosternum. 



d. Dorsum (or luesonotum). 

 t.s. Transverse suture. 



s. Scutellum. 



III. Metanotum. 

 mf. Metathorax. 

 h. Halteres. 

 Legs :— 

 c. Coxa. 

 /'. Femur. 

 't. Tibia. 



t.^. Tarsus (joints 1-5). 

 Abdomen: — 

 1-8. Abdominal segments 

 g. Genitalia. 



