MOVEMENT 



59 



the vast majority of families of this great order we find a 

 well- developed frenulum composed of numerous bristles 

 closely apposed, projecting from the costal base of the hind- 



, ^ - d 



Fig. 21. — Types of Wing-coupling Apparatus in various Insects. 

 a, Mecoptera (Taeniochorista), X 80 ; b, Neuroptera {Archichauliodes), 

 X 10; c, Lepidoptera (Micropterygidae : Sahatinca), X 80 : J, Lepi- 

 doptera (Hepialidae : Charagia), X 14; Cy Lepidoptera (Noctuidae : 

 Plusia), X 30. jl, jugal lobe ; jjugum ; &, jugal bristles (on forewing) ; 

 h, humeral lobe, and F, frenulum (on hindwing) ; r, retinacular 

 bristles on cubital nervure (r) of forewing. After R. J. Tillyard. (Proc. 

 Linn. Soc. N.S.W. xliii, 191 8.) 



wing and fitting beneath a number of stiff hairs or scales 

 under the base of the forewing (Fig. 21, e). Through such 



