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ENTOMOLOGICAL NEWS 



[Nov., '15 



of the Belgian author is that our serial sections through the posterior 

 5)art of the abdomen do not show a pair of independent "ventral 

 trunks" which he partially figures and describes. 



The tracheae which supply the rectum have been studied by a series 

 of transverse serial sections through the hind part of the abdomen of 

 larvae nos. 2 and 7. In spite of the unfavorable condition of the ma- 

 terial for a histological investigation, the tracheae were found to be 

 intact even to branches of small diameter (.002 mm.). The rectal epi- 

 thelium being in a much better state of preservation in larva no. 7, 

 the following brief description and the figures on Plates XVI and 

 XVII have been based chiefly upon that larva. 



The two great dorsal longitudinal tracheae, right and left, rdt, Idt, 

 each give off, in the anterior part of the eighth abdominal segment, a 



Text-figure 1. The principal tracheae supplying the alimentary canal in the poste- 

 rior half of the abdomen, Thautnatoneura larva, cf , No. 4. Dorsal view, x J3.3 

 For explanation of the abbreviations, see page 894. 



