THE EXO-SKELETON OF THE PROBOSCIS. 



153 



latest writer on the subject, says the plates which support the 

 palpi are maxillae, and the lancets, my lacinse, are mandibles. 

 For further information on the views held by various authors, 



FIG. 33. /, The trophi of a Flea removed from the head and seen from Jbehind : 

 a a, hinge of the maxillae ; l>, support of the ligula ; //, palpi ; / s, palpigerous 

 scale ; /, lacina ; lig, ligula ; psl, pseudolabium. 2, A portion of the same, seen 

 from its inner side : g, process of the hinge supporting the pseudolabium ; c, 

 articulation with the peristome ; /, process of the hinge which strengthens the 

 palpigerous scale ; d, articular head supporting the lacina ; e, articular extremity 

 of the lacina ; h, the base of the pseudolabium cut through ; the other letters as 



in /. 



which are exceedingly confused and conflicting, I must refer 

 my reader to Taschenberg and Gerstfeldt [55] . 



That both pairs of setae in the Diptera are parts of the 



