62 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 95 



the basal segments (coxopodites) of the gonopods of pterygote insects 

 are incorporated in the wall of the segmental annulus. The movable 

 claspers, together with the other genital processes that arise peripher- 

 ally from the segments of the genital region, may be designated col- 

 lectively the periphallic organs. 



DEFINITIONS OF EXTERNAL GENITAL STRUCTURES OF THE MALE 



The principal parts of the external genitalia and their commonly 

 developed accessories in male insects and other arthropods may be 

 named and defined as given in the following list of terms, but no 

 general nomenclature can be devised to include names for all the 

 minor modifications and special developments found in the various 

 orders of insects. 



Aedeagus (Aed). — The distal part of the phallus when the latter 

 has a dififerentiated basal part ; usually the principal part of the phallus, 

 or the entire organ if the phallobase is suppressed ; typically a sclerotic 

 tube with the phallotreme at its extremity. 



Bursa genitalis (GC). — The genital chamber of either the male or 

 the female ; in male insects a ventral invagination of the membranous 

 integument behind the ninth abdominal sternum containing the phallus 

 or phallic organs. 



Copidatory organs. — Any structures used by either sex for grasp- 

 ing or holding the partner during mating, or particularly paired organs, 

 usually segmental appendages, specially adapted or modified for copu- 

 latory purposes. 



Ductus ejaculatorius [Dej). — The median exit duct of the male 

 genital system ; if formed by the union of a pair of primary ductus 

 ejaculatorii it is a ductus conjunctus, if developed as a single median 

 invagination of the integument serving as an outlet for both vasa 

 deferentia it is a ductus communis. 



Ecto phallus. — The outer wall or exposed part of the phallus in dis- 

 tinction to the endophallus. 



Endophallus (Eiiph). — An inner phallic chamber invaginated at the 

 end of the ectophallus, and containing the true gonopore, or opening 

 of the ejaculatory duct; typically an eversible sac or tube, often mis- 

 taken for the end of the ejaculatory duct, but sometimes a permanently 

 internal phallic structure that may attain a complex development. 

 (Preputial sac.) 



Endotheca (Enth). — The inner wall of the phallotheca. 



Epimerc. — A dorsal process of the phallobase. 



