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NEW YORK STATi: MUSEUM 



been that some writers have employed the designation of Cecid- 

 omyia to represent a certain group of insects, while others have 

 used it in a totally different sense. The type of the genus D. 

 s 1 s y m b r i i Schrnk. is a well-known species, and a study of its 

 structures should forever obviate any further danger of confusion 



Fig". 1 8 D a s y n e u r a g i b s o n i , showing the general 

 characteristics of the genus (much enlarged, original) 



with the more typical Cecidomyia. The generic term Perrisia, pro- 

 posed by Rondani in 1846 for D. urticae Perris, agrees so 

 closel}- with D. s i s y m b r i i Schrnk. that we are unwilling to 

 accord it generic rank, despite the fact that there are certain well- 

 marked antennal differences l)etwecn the two. 



