186 R. E. SNODGRASS. 



Dicranomyia venusta Berg. (PI. VIII, fig. 1). 



This species is very similar to D. longipennis. The eighth seg- 

 ment, however, is much larger, its sternum is considerably prolonged 

 beyond the tergum (fig. 1), giving an upward bend to the end of the 

 abdomen. 



The tergum of the hypopygium rises almost vertically from the 

 eighth tergum. The pleura are large, each with a prominent lobe 

 near the distal end of the lower margin. The sternum is rudimen- 

 tary. 



The guard of the peuis and the penis are almost identical with 

 those of the last species. The guard is apparently a closed tube sur- 

 rounding the penis, at least, a careful examination revealed no groove 

 or even a suture along the dorsal line. If a specimen be allowed to 

 dry and then examined in liquid, the space around the penis within 

 the guard will be seen filled with air. 



The second gonapophyses are thin vertical plates projecting back- 

 ward from the front wall of the genital chamber. The distal con- 

 vex edge of each bears an up turned hook at the middle. 



Genus LIM\OBIA Meigen. 

 The members of this genus resemble those of Dicranomyia in hav- 

 ing the hypopygial sternum rudimentary. Both genera belong to 

 Osten Sacken's first group of the Tipulidae, the Limnobina. 



Limuobia sciophila O. S. (PI. IX, figs. 16, 19, 20). 



The abdomen is slender. The hypopygium does not form an 

 enlargement; it is somewhat upturned but is tapering. 



The eighth segment is simple, composed of a normal tergum and 

 sternum, the latter a little the larger. 



The tergum of the hypopygium is a plain transverse plate, placed 

 almost vertically, but constituting the true dorsal surface of the seg- 

 ment. The pleura are large plates entering the anterior margin of 

 the segment, expanded back of the middle and then again contrac- 

 ted. Each bears distally a large hook like lobe, the apical append- 

 age (figs. 16 and 19), which is greatly swollen at the base and direc- 

 ted inward and forward. 



The sternum consists of a narrow bridge uniting the anterior ends 

 of the parallel lower edges of the pleura. From the dorsal side of 

 this bridge arises the penis and its guard. The guard (fig. 20, p, g) 

 consists of a median plate grooved along the middle line above, ex- 



