ANNALS 
OF 
The Entomological Society of America 
Volume XIV MARCH, 1921 Number | 
THE IMPUDICA GROUP OF THE DIPTEROUS GENUS 
TIPULA LINNAEUS. 
By W. G. Dietz, M. D. 
A sharply defined, natural group of the genus Tipula 
Linnaeus, characterized as follows: Hypopygium of the male— 
the genital chamber widely open above, (Pl. I, Figs. 1, 2; 3, 4 
5, 6, 6a). The ninth tergite relatively short, the ninth sternite 
much prolonged beyond the former. The ninth tergite deeply 
incised in the middle (except madina), the sides emarginate, 
the lateral portion more or less distinctly incurved beneath, 
(Prt Fis. 6c). The incurved margin generally: ends in a 
sharp spine, (Pl. I, Fig. 6c), visible in some species (impudica, 
dimidiata, Pl. I, Figs. 6b, 8) from above. From the lateral 
inflexed margin extends a thin shelf or lamina, which bears in 
the middle a process, compressed and sharply pointed, (except 
byramis pellucida, where it is broader and obtuse), the upper 
margin of which fits into the median incision of the tergite, 
(Pl. ¥, Figs. 6b, 6c, 8, 9). This process I designate as the 
subtergal process. Ninth sternite ample, more or less deeply 
emarginate. Pleurites ample, subtruncate or more or less 
cone-shaped. Pleural suture present, abbreviated (Pl. I, Fig. 
la). The outer apical appendages are small and inconspicuous, 
narrowly lanceolate, curved cephalad, the apices abut into 
or lie beneath the lateral emargination of the ninth tergite, 
Pl. I, Figs. 1, 2, 3, 4, 5, 6, 6a). The inner apical appendages 
more conspicuous, the posterior portion laminate and sub- 
cautinous with the lower apical appendages; the anterior portion 
is elevated and consists of two more or less distinct, narrow 
perpendicular blades (Pl. I, Fig. la), which are strongly chiti- 
nized and the anterior end of the inner blade overlaps the 
