LSO Journal New York Entomological Society. [Voi. xi. 



U-shaped with a Y-shaped bar between the arrow, having the forked 

 part posterior. 



These forms described are typical of the genus Tipula. The follow- 

 ing species are all very similar to T. angustipennis : T. bisetosa Doane, 

 T. cBqiialis Doane, T. caloptera Loew, T. lamellata Doane, T. flavi- 

 co/Zi's Fab., T. tephfocephalal^oew, T. cinerea Coq., T. triinttaV>oz.x\&, 

 T. fallax Loew, T. brevicoUis, T. incisa Doane, T. iinpiidica Doane, 

 T. truncorum Meig., T. cognata Doane, T. spernax O. S., T. ciispi- 

 data, T. inermis Doane. 



Tipula bicornis. (PI. X, Fig. i, and PI. XI, Fig. i6.) 



This species and the next described depart from the general form 

 for the genus more than do any others examined. In T. bicornis the 

 eighth sternum is unusually large and prolonged posteriorly as far as 

 the lips of the very short cerci. It bears at the end two very short, 

 vertical, apical lobes (Fig. i a'). The tenth segment is very short, 

 the cerci {cer.^ are small and spatulate. The ninth sternum consists 

 of a bilobed plate having the form shown in Fig. i6. 



Tipula streptocera Z^cw;/^. (PL XI, Fig. 19.) 



Of the same type as the last, but the ninth tergum is shorter and 

 is deeply notched above on the posterior margin. Both eighth tergum 

 and sternum large, apical appendages of the latter small. Ninth 

 sternum (Fig. 19) consists of two leaf-shaped plates, each produced 

 posteriorly and inward as a long stem-like process, the two stems 

 fusing into a median point. Tenth segment consists of a narrow 

 transverse band expanded triangularly on dorsum. Cerci are short, 

 vertical, semicircular plates. 



No other species in the collection were found of the bicornis and 

 streptocera type. The males of these species present the same type of 

 structure in the form of the hypopygium but they differ greatly in 

 degree of development of certain parts. For example, in each a process 

 projects backward from the "pleural " plates, but in T. bicornis they 

 are short and inconspicuous, while in T. streptocera they form a pair 

 of long rod-like arms projecting posteriorly and upward. 



All the lower genera show the same plan of structure as does 

 Tipula. Their species differ in various minor ways from the species 

 of this genus, but there are no generic and super-generic variations in 

 the female genitalia as there are in the male hypopygia. 



