Crop in the Mallophaga. 



267 



ants* and in the Odonata Zygoptera f. In the Amblycera 

 the crop-teeth assume characteristic forms in the different 

 genera, and could be used with advantage in classification, as 

 they are of generic if not specific value, and, as a rule, are 

 easily visible through the integument in mounted specimens 

 prepared with caustic potash. 



The following is a short description of the position and 

 nature of these teeth in different genera. 



Sketch of alimentary canal of Goniodea faleicornis. 

 a, oesophagus; b, ventriculus; c, crop ; d, patch of teeth. 



ISCHNOCERA. 



The crop in the Trichodectidaj is apparently devoid of 

 teeth. I have carefully examined with a high power the 



* Sharpe, D., Camh. Nat. Hist., Insects, part i. p. 1 :.'.">. 

 t Higgins, Helen T., Proc. Nat. Sci. of Philadelphia. Jan. 



1901, 



