162 



of the piercing flies and the flexible, sensitive . ligula of the bees. In 

 the structure of the galea, yet more marked changes occur, the differ- 

 ence between the palpiform organs in someColeoptera, the united rigid 

 beak-like form in the Hemiptera, the flexible coil-like structure in the 

 Lepidoptera, and the peculiar tongue-like organ in some Diptera being 

 vastly greater than anything seen in the palpifer. In the Panorpidse of 

 the order Neuroptera Tve have, however, a development of the palpifer, 

 which is not rigid, but is membranous, though not flexible, and which 

 is set with hair which, in part at least, is tactile in function. 



'F1GA2.— A, Ma^Ua. of Pronuba cT c, cardo; s, stipes; pfr, palpifer; p, palpus; gr, galea. ^.Maxilla 

 of Nemognatha. s, stipes; pfr, palpifer: p, palpus; g, galea; Z,lacima. C.p, palpus; j5/r, palpifer of 

 Erax. Z), Maxilla of Pron-M&a 5 c, cardo ; s, stipes; pfr, palpifer; p, palpus; gr, galea. E. Maxi l la of 

 Bittacus, c, cardo ; s. stipes; pfr, palpifer; p, palpus; g^, galea, first joint; g^, galea, second joint; sg, 

 sub-galea; I. lacinia. (From drawings by John B. Smith.) 



In this same family of Panorpidse we have, by the by, a most re- 

 markable examxDle of the elongation of the mouth parts. The lacinia is 

 small, yet obvious ; the subgalea is elongated from each side, forming 



