THE EXO-SKELETON OF THE PROBOSCIS. 



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a basal joint, the cardo, c, which supports the stipes, s, or second 

 joint. Three lobes are articulated with the stipes the first, 

 or external lobe, is usually reduced to a small scale which sup- 

 ports the palpus ; it is the palpiger, p' '. The second lobe, or 

 upper lobe of Kirby, frequently forms a large hood in which the 

 third, or internal, lobe lies when at rest. This second lobe is 

 the galea, g. It almost always consists of, at least, two joints, 

 and is usually soft and fleshy. In a few Coleoptera, as the 



FIG. 26. Details of the Maxilla and Labiuni, after Brulle : /, maxilla of Locusta 

 viridissima ; 2, of Blaps ; J, of Pepsis sp. ; 4, of Xylocopa violacea ; J, of an 

 Australian species of /Eschna : $, galea; /, lacina : g' , sous-galea ; s, stipes; 

 p', palpiger ; c, cardo ; 6, labium of Copris Isidis : /', lacina or inner blade of 

 second maxilla ; //>, ligula ; ^', outer lobe (galea) ; /, palpus. 



Tiger-Beetle (Cicindela), the galea is palpiform, and is usually 

 termed the second maxillary palpus [Newport, 9, p. 890]. The 

 third lobe, or lacina, /, is frequently a cutting blade, and some- 

 times has a small claw, the uncus, articulated with it near its 

 extremity. In some phytophagous insects the lacina is con- 

 verted into an obtuse lobe covered with setae. 



The improbability that so complex a structure can become 

 a mere seta is, to my mind, very great ; but when it is 



92 



