NORTH AMERICAN TWO-WINGED FLIES OF THE GENUS 

 CYLINDROMYIA MEIGEN (OCYPTERAOF AUTHORS) 



By J. M. Aldrich 



Associate Curator, Division of Insects, United States National Museum 



In the preparation of this paper the Avriter has studied the mate- 

 rial contained in the United States National Museum, including his 

 own earlier collectino-; the Canadian National Collection; the Uni- 

 versity of Kansas; the California Academy of Sciences; and the 

 private collections of C. W. Johnson, James S- Hine; A. L. Melander, 

 H. J. Reinhard, and H. W. Allen, together with a few specimens 

 from various other sources. The total number of specimens ex- 

 amined is nearly 800. Special acknowledgment is gratefully made 

 to C. Howard Curran, who when he learned of my work turned over 

 all the material of the Canadian National Collection with a partly 

 prepared paper and numerous drawings. R. E. Snodgrass kindly 

 prepared drawings of the remarkable holding apparatus of the 

 females of CylindroTnyia nana. Several European species deter- 

 mined by Prof. M. Bezzi are in the United States National Museum, 

 and have been very useful. 



The genus C ylimlroniyia was described by Meigen in his famous 

 1803 paper, the real beginning of dipterous taxomony. Two years 

 later Latreille described the same genus, with the identical genotype, 

 as Ocyjjtera. Meigen, solely out of deference to his distinguished 

 colleague, as far as can be perceived now, waived his own priority 

 and adopted Ocyptera in his next treatment of the genus in 1824. 

 This disposition of the names was accepted for many years. Osten 

 Sacken cited this case in his paper on Priority or Continuity? in 

 1882, as an illustration of the undesirable effect of too strict enforce- 

 ment of priority. Professor Bezzi later argued that Ocyptera was 

 included in Latreille's 1802 volume, and hence really was prior; that 

 this was an error was not discovered until after he had published his 

 third volume of the Palaearctic Catalogue. Coquillett, in his Type 

 Species paper of 1910, accepted Cylindromyia^ and was followed by 

 Townsend in 1912. 



No. 2624.— Proceedings U. S. National Museum, Vol. 68, Art. 23. 



70648—26 1 1 



