106 NORTH AMERICAN TIPULIDAE 



111 my investigations of numerous individuals representing a 

 large number of species from within our faunal limits, the hypo- 

 pygium presents two characters which, independent of others, 

 I consider well-nigh characteristic of the genus. They are, 

 the ninth tergite never longer than wide, generally short, trans- 

 verse, impressed above mesially, the free margin incised or emar- 

 ginate in the middle and the lateral angles never acutely extended. 

 The outer apical appendages — upper of Snodgrass — are lan- 

 ceolate (broadly in P. oslari), acuminate, frequently attenuated 

 and incurved beyond the middle. In connection with these 

 hypopygial characters, others will invariably be present to estab- 

 lish the generic status of a given species. These having suc- 

 cinctly been stated by Alexander,^ I merely wish to comment on 

 some and add others observed by myself : 



1. The short and stout proboscis, together with the rather 

 short and stout first antennal joint, mentioned by Schiner,^ 

 are present in all of our species (except calif ornica, mentioned 

 hereafter) . 



2. The radical sector is longer, semi-oblique, with vein, S. c. 

 ending at some distance beyond its origin (Pachyrhinae 

 tipuloides) , or else, short and oblique in a variable degree, with 

 vein S. c. ending in close proximity to its origin {Pachyrhinae 

 s. s.). 



3. The presence generally of S. c\ as a cross vein, in Pachyr- 

 hina^ (absent in oslari, hyhrida, partially atrophied in pachyr- 

 hinoides, calinota) ; absent in Tipida (present in oropezoides, dor- 

 solineata) . 



4. Cell M\ when sessile or very shortly petiolate, is character- 

 istic when present. A petioled cell M^ occurs frequently and 

 varies considerably in length of its stem, not only in different 

 individuals of the same species, but even in the two wings of the 

 same individual. (Doane^"). According to Schiner,^'^ speci- 

 mens of Tipida nigra occasionally occur, with cell M^ sessile. 



' Op. cit., p. 466. 



8 Op. cit., ii, p. 503. 



* Prof . Needham in his "Key to the North American genera of craneflies" 

 (Report of the New York State Museum, 1907, p. 244), says under aa-b-Sc.^ 

 wanting-Tipulinae. In the footnote, same page, specifically includes Tipula 

 and Pachyrhina. 



i» Entomological News, 1908, p. 179. 



11 Op. cit., ii, p. 503 footnote. 



