874 



Charles Paul Alexander 



specialized forms, and are difficult to homologize even in species that 

 are unquestionably closely related. This condition occurs in several other 

 groups, as in the mycetophilous genus Sciophila and related groups, 

 according to Dr. Johannsen, who has studied the family. In Acyphona 

 and other genera the hypopygium is asymmetrical in relation to the 

 remainder of the abdomen, the ninth abdominal segment being twisted 

 half around. In some limnophiline forms (Phyllolabis, Oromyia, Limno- 

 phila mundoides) the hypopygium is enlarged and complex, suggesting 

 the condition found in many species of Tipula; in Phyllolabis the eighth 



Venfra/ 

 pleura/ 

 appendagew 



Dorsa/ 

 p/eura/ 

 appendage 



Venfraf 

 pleural 

 oppendai^e 



pleunte 



Dorsc7/ 



pleural 

 appendage 



Dorsal 

 pleural 

 appendage 



A B C 



Fig. 130. male hypopygium, limnobiinae 



A, Geranomyia rostrata, dorsal aspect. B, Gonomyia amazona, ventral aspect. C, Chionea 



primitiva, dorsal aspect 



sternite bears a pale foliaceous appendage, while in Oromyia the ninth 

 sternite is produced into a conspicuous lyriform plate. In Chionea 

 (fig. 130 c), Cladura, and Pterochionea, there is a single powerful pleural 

 appendage on each side. 



The normal type of structure in the Limnobiinae consists of short to 

 elongate pleurites, bearing at or near the apices two or three appendages 

 which are usually chitinized and decussate in a position of rest. The penis 

 guard occupies the ventral area of the genital chamber, the anal tube 

 the dorsal area. 



The female hypopygium. — The female hypopygium, or ovipositor, is 

 characteristic in many species of the Tipulidae. In most cases it consists 



