448 



COMPARATIVE ANATOMY 



CHAP. 



and agree in all essential points with the Orthopteran type above described. The 

 composition of the lower lip out of 2 maxillse is especially clearly shown in the 



Aptera. Both pairs of maxillse possess 

 well developed palps. 



Pterygota. The mouth parts of the 

 Orthoptera were described and illustrated 

 above. As, however, .the mouth parts 

 of other orders of the Insecta deviate 

 markedly from these, it is necessary to 

 describe the more typical forms or 

 arrangements. 



A knowledge of the mouth parts of 

 a small family of the MicroUpidoptera, 

 the Micropterygina, throws light on the 

 mouth parts of the Lepidoptera. We 

 here still find the typical parts : (1) 

 toothed mandibles, capable of mastica- 

 tion ; (2) anterior maxillae, with separate basal portions, with 6-jointed palps and 2 

 e masticatory ridges ; and (3) a lower lip (posterior maxillfe) whose basal 



cm. 



FIG. 306. Mouth parts of a Macrolepidop- 

 tera larva (Ocneria). Lettering as in Figs. 303 

 and 309. 



FIG. 307. A, Mouth parts of the Macrolepidoptera. B, The lower lip (2d pair of maxillfe), 

 isolated. Lettering as before, sr, Sucking proboscis, corresponding with the fused ridges of the 

 1 st pair of maxillae. 



portions are fused into one common piece, but carry 3-jointed palps and masticatory 

 ridges still distinctly separate. The 2 inner ridges have grown together and form 

 a short tube. In the other Microlepidoptera the mandibles lose their teeth and 

 become rudimentary. On the anterior maxillae only 1 ridge is found. The ridges 



