198 AN ESSAY ON THE DEVELOPMENT OF THE MOUTH PARTS OF CERTAIN INSECTS. 
Fig. 
Fig, 
GU Gp Gl 
© 2 
Plate I. 
Mouth structures of Asilide—Laphria sp. a, maxilla from front ; b, same from behind ; ¢, labium ; d, lab- 
rum ; é, transverse section of mouth at junction of galea and subgalea. 
Mouth structures of Ramphomyia longicauda. a, the labium ; 6, maxilla; c, extension of front of head ; 
d, relation of this extension to the labium. 
Galea of an Andrena allied to vicina. 
Mouth parts of Bittacus strigosus. a, mandibles and labrum; 2, maxilla and labium; c, mandibles and 
labrum—epipharynx of Panorpa rufescens. ; 
Labial structures of Hristalis tenaz. 54, transverse section at about middle ; 5), same at about tip. 
Labial structure of Bombus sp. 62, transection at about middle ; 6b, same made near tip. 
Labium of Harpalus calignosus. 
Maxilla of Pertplaneta orientalis. 
Maxilla of Perlid larva. 
Epipharynx of Hristalis tenaz. 
Mouth parts of Bibiosp. a, maxilla from behind ; 6, same in front ; c, transection made near the base. 
Labium of Bombus fervidus ; the transections are lined to the portions referred to. 
Labium of Chrysops vittatus ; the transections are lined to the parts referred to. 
Labium of Hermetia mucens. 
Maxille and labium of Bombus, showing the relation of the parts to each other. 
Maxilla of Stalis. 
Maxilla of Hydrophilus from upper and Jower surface, redrawn from Comstock. 
Maxilla and labium of Pteromalus, redrawn from Ashmead. 
Maxilla of Pronuba, male. 
Maxilla of Wemognatha. 
Maxilla of Pronuba, female. 
Mouth parts of Locusta from Kolbe. 7, labrum ; 7, mandibles ; 772, maxille ; ¢, labium, 
