EXPLANATION OF PLATE IL 



Fig. I. — Mr. Burrows' specimen of Acronycta tridens. x 5. 



Fig. 2. — Extremity, x 16, to be compared with fig. 4, showing the normal 

 appendages. Fig. 2 has only the basal ring, i.e. the tegumen and 

 uncus. The remainder of Fig. 4 is represented in Mr. Burrows' 

 specimen by the portions shown in Fig. 3 ( x 16), where, though 

 coiled together, they can all be made out, excepting the spiculated 

 eversible membrane, which seems to be badly developed rather 

 than absent. Fig. 3 also shows the two cups that probably are the 

 male pupal tubercles. These seem quite different structures from 

 certain very remarkable dark bodies that Mr. Pierce finds in the 

 abdomina of some species, but whose nature is not yet determined. 

 (Photos by F. N. Clark.) 



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