NO. 14 INSECT ABDOMEN — SNODGRASS 63 



Epiphallus (Epph). — A large, transverse sclerite developed in the 

 dorsal wall of the base of the phallus, characteristic of Acrididae. 

 (Pseud osternite of Walker.) 



Genital chamber (GC). — See bursa genitalis. 



Genital segment, or gonosomite. — Specifically the body segment 

 bearing the openings of the primary genital ducts, or the segment with 

 which the median gonopore is most closely associated, but also in a 

 wider sense any one of the segments in a specially differentiated genital 

 region of the body. In insects the genital segment is primarily the 

 seventh abdominal somite in the female and the tenth in the male, but 

 secondarily the female genital segment is usually the eighth or the 

 ninth abdominal somite, and that of the male the ninth. 



Gonapophysis (Gon.). — Any part of a segmental appendage closely 

 associated with the genital segment and having some function inti- 

 mately related to intromission of the sperm by the male or the deposi- 

 tion of eggs by the female. In male Malacostraca the gonapophyses 

 are the endopodites of the first and second abdominal appendages and 

 serve as intromittent organs ; in insects the gonapophyses are appar- 

 ently endites of the appendages of the eighth and ninth abdominal 

 segments, present in both sexes of some Thysanura, forming the usual 

 ovipositor of female insects. 



Gcnopod (Gp). — An appendage of the genital segment or of an 

 associated segment modified for some purpose in connection with 

 copulation, intromission, or oviposition. 



Gonopore (Gpr). — The external opening of a genital duct, whether 

 exposed, or concealed in a secondary invagination of the integument, 

 such as the genital chamber or an endophallic cavity. 



Gonostyli. — The styli of the ninth abdominal segment of some male 

 insects, presumably appendicular parts of the coxopodites of the gono- 

 pods, probably homologous with the movable claspers (harpagones) 

 of many insects. 



Gonotreme (Gtr). — The external opening of the bursa genitalis, 

 or genital chamber, in either sex ; the vuiva of the female. 



Harpagones (Hrp.). — Movable periphallic appendicular organs of 

 the ninth abdominal segment of the male, individually provided with 

 muscles, probably derivatives of the gonostyli, sometimes supported 

 on distinct coxopodite plates. (Valvae, harpes.) 



Hypandriiim (IXS). — The subgenital plate of the male, usually the 

 sternum of the ninth abdominal segment. 



Hypomere. — A ventral process of the phallobase. 



Intromittent organs. — Any structure of the male serving for the 

 introduction of the sperm or spermatophores into the female, in some 



