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 maxilla; is especially clearly shown in the 



Aptera. Both pairs of maxilla; 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 Microlcpidoptc.ru, 

 the Micro2)terygiiia, throws light on the 

 mouth parts of the Lepidoptcra. 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 

 separate masticatory ridges ; and (3) a lower lip (posterior maxilla;) whose basal 







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 maxillae), 



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

 3 st pair of maxillte. 



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 maxilla; 



only 1 ridge is found. 



The ridges 



