No. 64] DIPTERA OF CONNECTICUT: MORPHOLOGY 109 



aedeao'iis to tlie rio-id portion Avhich serves to ciiide the membranous 

 penis, which is exserted by blood pressure. The designation intro- 

 mittent organ might be applied to the entire organ, although some 

 writers are inclined to restrict this designation to the penis alone. 

 The terms phallosome* and aedeagus are the ones most frequently 

 applied to the external sclerotizecl portion of the genital tube by 

 recent dipterists, and AVesthof's term adminiculum is seldom em- 

 ployed by them. 



In a typical muscoid fly such as Phormia regina shown in Fig. 

 10, E, and Fig. 1J:„E, the aedeagus is composed of a distal portion, 

 or phallus, jiha, and a basal portion or phallophore, pho^ which bears 

 the phallus. Huckett (1924), who adopts the terminology proposed 

 by Metcalf (1921) for the Syrphidae, calls the phallophore and 

 phallus the "chitinous box" and "ejaculatory process" in the An- 

 thomyidae, although this application of the designation "chitinous 

 box" is not exactly the same as that employed by Metcalf. Carpenter 

 and Hewitt (1914) apply the designations juxta and theca to the 

 phallophore or basal portion of the aedeagus in H y poderma^ while 

 Newstead (1911) refers to the part in question as the juxta or penis 

 sheath in Glossina. Hendel (1928) refers to the phallophore and 

 phallus as the theca and phallus, apparently adopting the designation 

 "theca" from Wesche (1906), wdio first applied it to the basal region 

 here designated as the phallophore. 



It is inadvisable to apply the designation "theca" to the basal 

 region of the aedeagus labelled pAo in Fig. 10, E, Fig. 14, E, etc., since 

 the term theca is also used to designate a wide range of structures in 

 the Diptera. and in other insects as well. Thus Hendel (1928) applies 

 the designation "theca" to the hyoid sclerite in the labium of the 

 Diptera, and also applies the same term to the basal region of the 

 aedeagus as well in these insects, while most of the recent students of 

 the Diptera apply the designation theca to the sclerite of the labium 

 here designated as the prementum. The coccidologists, on the other 

 hand, apply the designation "theca" to the crumena of the coccids, 

 and other entomologists refer to the outer covering of pupal insects 

 as the "theca", and there is such great confusion in the application 

 of this term that it is preferable to drop it altogether. 



Lowne (1893-1895) refers to the phallic spine labelled goa in 

 Fig. 13, E, and Fig. 10, E, etc., as the epiphallus, and this term is as 

 appropriate as any that have been applied to it. Hewitt (1914) calls 

 it the superior apophysis in the housefly, Avhile Wesche (1906) calls 

 it the spinus titillatorius, and Huckett (1924) refers to a similar 

 structure in male anthomyids as the ejaculatory hood, although the 

 latter designation is not used in exactly the same sense as that em- 

 ployed by Metcalf (1921), who introduced this term in his descriptions 

 of the parts in male Syrphidae. 



Lowne (1895) applies the designation paraphallus to the parts 



* students of the Tipulidae restrict the designation phallosome to tlie structure 

 at the base of the aedeagus ae of the tipulid shown in Fig. 7, J, and this usage has 

 much to recommend it. 



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