CALLIPHORA ERYTHROCEPIIA LA, MG. 



289 



Remarks ox some Specialised Types of Proboscis in the 



m i'scidae. 



Considering the Muscidae alone, we find an enormous pre- 

 ponderance of a type similar to that of the Blow-fly, but with 

 two other well-marked forms : (a) An elongation of the proboscis 



8. The same, but the intercalary veins present in the Tabanidae and lost 

 in the process of simplification are indicated by dotted lines, showing 

 the close approximation of the two types. 



4. Wing of the Blow-fly (CaWphora erythroeephala, Mg.), showing the 

 actual venation. The bend of the fourth vein has been modified to 

 afford increased stiffening to the distal portion of the wing, and 

 consequent!}- greater powers of flight. 



accompanied by a geniculation of the labella, which bear well- 

 developed though simplified tracheae, enabling the insect to 

 penetrate the cavities of flowers and suck the juices (Plate 23, 

 Fig. 1 ) ; and (b) a chitinising of the proboscis, owing to a greater 

 development of the mentum, modifying the proboscis into a hard 

 style, fitted for penetrating skin and sucking blood (Plate 23, 



