WILLIAM G. DIETZ 105 



A REVISION OF THE NORTH AMERICAN SPECIES OF 



THE TIPULID GENUS PACHYRHINA MACQUART, 



WITH DESCRIPTIONS OF NEW SPECIES 



(DIPTERA) 



BY WILLIAM G. DIETZ, M. D. 



In his excellent paper on Moravian Tipulidae, Czizek 1 rele- 

 gates Pachyrhina Macquart to the synonymy of Nephrotoma 

 Meigen, and, as much as Alexander 2 accepts this view and applies 

 it, it may be well to state the writer's reasons for retaining the 

 generic name Pachyrhina. Schiner 3 separated Nephrotoma as 

 distinct from Pachyrhina. The type and sole European species 

 is Nephrotoma {Tipula) dorsalis Fabricius, and it is differentiated 

 from Pachyrhina by the nineteen-jointed antennae of the male 

 (fifteen-jointed in the female). Its Nearctic representative on 

 the Western Continent is Pachyrhina eucera Loew. All the 

 other recognized species of Pachyrhina, with the exception of 

 P. polymer a Loew, have thirteen-jointed antennae in the male. 

 Without wishing to invalidate the claim of priority of Nephro- 

 toma, I deem it expedient to retain the genus as distinct from 

 Pachyrhina. The type of the latter is P. crocata Linnaeus, a 

 black species with yellow markings and thirteen-jointed antennae. 



From the time of its erection (1834), Pachyrhina has been ac- 

 cepted by all writers on the subject, and its relegation to synon- 

 ymy could only result in confusion without offering any scientific 

 advantage. It is not sharply defined from Tipula and its 

 definition, as stated by Alexander 4 and recognized by other in- 

 vestigators, depends rather on an aggregation of characters than 

 any one in particular. Czizek 5 in his work and also Brunetti, 6 

 have adduced certain venational characters, which if constant, 

 would appear to be decisive. 



1 Tipulidae Moravicae, Zeitschrift des Maerischen Landesmuseums, ii, p. 50, 

 (1911). 



2 Proceedings of the Academy of Natural Sciences of Philadelphia, 1915, p. 465. 



3 Fauna Austriaca, ii, p. 502. 

 * Op. cit., p. 466. 



5 Op. cit., p. 50. 



6 Fauna of British India, p. 340, (1912). 



TRANS. AM. ENT. SOC, XLIV. 



