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 
Vertral Dorsal Dorsal 
pleural pleural 
_ Pppendage appendage 
'Dorsa! 
4 - Pleural 
apperdage 
A B Cc 
Fic. 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. 180 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 
