EXPLANATIONS OF PLATE II. 



Fig. 1. Side view of the head of Bombylius major with its proboscis; at the 

 upper right-hand corner are figured the tips of the labrum-epipharynx, 

 hypopharynx and maxilla, to illustrate their comparative sizes and 

 lengths. Below ( 2') is a series of cross-sections of various parts 

 of the proboscis and its base. 



Fig. 2. View of the head of B. major from above, to show how the labellae 

 open. 



Fig. 3. Longitudinal section of the head of B. major, z, location where the 

 ventral posterior process of the fulcrum lays, d, location of the 

 dorsal posterior process of the fulcrum. 



Fig. 4. Tip of maxilla of B. major. 



Fig. 5.- Perspective view of the chitinous portions of the pseudotracheae of 

 B. major; a, while at rest; b, while feeding. 



Fig. 6. Cross - sections of the pseudotracheae of B. major when the two 

 labellae are opposed to each other; a, at rest; b, while feeding. 



