BOTH THE SEXES IN DIPTEEA, 365 



Stratiomyiidcc. — In the StratiomyiidgB they are more oval in shape and have charac- 

 teristic long chitinized tubes, which continue for a similar distance in a hyaline 

 condition, and are three in number. 



Tabanidce. — In Tabmms bovimis, Hcematopota phwicdis, and S. crassicornis the recep- 

 tacula are peculiar, relatively small, quite pyriform in shape, attached to exceedingly 

 long tubes whose circumference is only a little less than that of the receptaeula. They 

 end in muscular outgrowths, which have the appearance of columns, the capitals being 

 formed of a transverse plate which the tube pierces ; these outgrowths penetrate the 

 walls of, and open into, the oviduct. They are three in number (PI. 30. figs. 123, 128). 



Asilidce. — Three globular receptaeula with long muscular ducts are found in the 

 Asilidae. 



Bombylidce. — A similar arrangement and number of receptaeula to that of the 

 Tabanidaj are found in Comptosia ocellata. 



Mnpid(B. — I have only found one receptaculum in the females of the Empidge that I 

 have examined. 



LoUchopodid(B. — In the Dolichopodidfe, as well as several other families, the recep- 

 taeula are not chitinous and do not show in my preparations. But the rectal papillae — 

 four glands which surround a portion of the anal passage and whose exact function is 

 not clearly demonstrated — are very prominent. They are shown on the ultimate segment 

 of the ovipositor of DoUchopus griseipeimis (PI. 25. fig. 52), but this gives no real idea 

 of their true form ; they are cone-shaped, the base is a chitinous hoop which has some 

 very fine aculeations scattered on its surface. This hoop rests on a membrane with 

 tracheae in its structure, and supports a transparent or subtransparent cone which is 

 studded with numerous curious laminae, which have one of the edges pectinated, 

 resembling a scale of Lepidoptera (PL 30. figs. 124, 125). 



They are present in equal development in both sexes, and are very evident in several 

 species of DoUchopus, as well as in Fa'cilobothrufs. 



This part is, strictly speaking, not in the subject-matter of tliis paper ; but as the 

 receptaeula in this family are difficult to find, and appear to be of a different structure 

 from that which is usually found associated wath the part in Diptera, I think it as well 

 to draw attention to them, especially as they appear in PI. 25. fig. 52, and as they might 

 easily be mistaken for receptaeula, unless the observer was lamiliar with Lowne's * 

 description of those organs in Calliphora. 



Syrphidce. — In Syritta p/'piens and Eristcdis tenax the receptaeula are three in 

 number, are of a flattened oval shape, and carry long tubes. 



Muscidcc. — In the Muscidae three receptaeula are usually found ; but my prepara- 

 tions of Stomoxys calc'drans (Linn.), TLcvmatobia stimidans, Meig., Glossina mo7's'daiis, 

 and G. palpcdis only show two receptaeula. In the Anthomyzida; the receptaeula are 

 three in number, and often have marks on the cuticle quite distinctive of the species. 

 Anthomyia radiaum has short dark papillae on the surface (PI. 30. fig. 133). Uomalomyia 

 manicata, Meig., shows short spines on the inside cuticle. Uylemyia cinerosa, Zett. (?), 



* ' Blow-fly,' pp. 417-418. 



53* 



