A SYNOPSIS OF THE DESCRIBED NORTH AMERICAN SPECIES 

 OF THE DIPTEROUS GENUS TIPULA L. 



By W. G. DiETZ, M. D. 



The following synopsis is not offered to fill the proverbial 

 long felt want, but rather that it may facilitate and lessen 

 the labor of the student who undertakes the study of the 

 above mentioned genus. It is based almost entirely on the 

 original descriptions with the exception of those of Fabricius, 

 and for these I have had to depend upon those of Wiedemann.* 



Many of these fall short of completeness. Some, like those 

 of Walker's, as was his custom elsewhere, are woefully 

 defective. Fortunately not a few of these have been authen- 

 tically recognized and wherever such was the case and rep- 

 resentative material was at hand, I have drawn upon this 

 source of information. It will readily be seen that this synopsis 

 is not merely a synoptical table in the usual sense and hence, 

 some explanatory remarks are deemed necessary. To give 

 more certitude to the identification of a given species, the 

 usual differential diagnosis is followed by a short detail 

 description. In the latter, especial stress has been laid upon 

 the structure and formation of the hypopygium — ninth seg- 

 ment — and the eighth abdominal segment of the male, though 

 in many instances no information on these points was available. 

 All references to the apical appendages of the male hypopygium 

 have been omitted, important and almost absolute their con- 

 sideration becomes in the separation of otherwise very closely 

 allied or similar forms, as this would have led far beyond 

 the scope of this paper. It must be remembered that all 

 references to the eighth and ninth — hypopygium — abdominal 

 segments refer to the male, unless otherwise stated. f 



In the use of the synopsis, a certain margin must be allowed 

 for the interpretation of terms used. I have, as nearly as pos- 

 sible made use of the identical language of the authors in their 

 descriptions and in the translations from the Latin have kept 

 close to the sense of the writer. What to one observer might 



* Aussereuropaeische zwei fluegelige Insecten. Vol. I. 



fThe term "ninth tergite " and " ninth sternite " in the text are the equiva- 

 lents of "upper and lower lamella," respectively, used by writers. 



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