No. 61] DIITERA OF CONNECTICUT: MORPHOLOGY 105 



9t, of Fif,^ 12, F, and Fig, 13, E, as the tenth segment in the Syrphidae 

 and Muscidae, while Hewitt (1914), Parker (1914), and Lowne (1895^ 

 consider that it represents the eighth segment in the higher Diptera, 

 but most of the recent students of the muscoid flies agree in inter- 

 preting this segment as the ninth, since it bears the male genital organ 

 which is an "appendage" of the ninth segment in male insects in 

 general. 



Of the various interpretations of the ]iarts of the postabdomen 

 of the muscoid Diptera discussed aboA'e, those proposed in the fine 

 paper by Cole (1927) are the most nearl}^ in accord with those ac- 

 cepted here. The principal difference between Cole's interpretation 

 of the segments of the postabdomen, and the interpretation suggested 

 here, is that Cole considers that the eighth sternite of one of the 

 muscoid flies such as Hylemyla shown in Fig. IB, D, is represented by 

 the sclerite here interpreted as the sixth sternite, labelled 66- in Fig. 

 13, D, (Cole states that the eighth sternite is represented by "a nar- 

 row strip on the left side" in Hylemyia., and labels the sixth sternite 

 as the "eighth" in his Fig. 213 of this insect) ; and Cole considers that 

 the sclerites labelled 7^ and 8s in Fig. 13, D, of HyJemyia represent 

 the seventh and eighth "tergites" in this insect, instead of represent- 

 ing the seventh and eighth sternites, as they are here interpreted. 



The terms which have been applied to the parts of the copulatory 

 apparatus of male muscoid flies by various workers in this group are 

 listed in the following discussion, in which the terms Avhich appear 

 to be the most appropriate, or those which are the most widely ac- 

 cepted, have been selected for describing the parts in a typical mus- 

 coid fly represented by Phonnia regina shown in Fig. 13, E, and Fi^. 

 10, E, etc. 



The fifth sternite. or last sternite of the pi-eabclomen of Phormia. 

 is deeply cleft ])osteriorly to form a pair of posterior lobes labelled 

 pgl in Fig. 13, E, or Fig. 10, E, etc. These lobes, or processes, are 

 frequently used in mating, and therefore may be included among the 

 "copulatoria" or general structures used in copulation, but they should 

 not be included among the "terminalia", as is done by Patton (1932), 

 since the terminalia are parts of the postabdomen lying behind the 

 fifth, or last sternite of the preabdomen. 



The lobes or processes of the fifth sternite {lygl of Fig. 13, E) 

 are sometimes referred to as the pregenital lobes (or processes) by 

 dipterists, although Patton (1932) states that the designation pri- 

 mary forceps (used by Hewitt. 1914, and others) is the one usually 

 applied to them. Awati (1915) calls these lobes the accessory for- 

 ceps, Parker (1914) refers to them as the lamellae, and AVesche (1906) 

 calls them the laminae "superiores", although they are ventral in posi- 

 tion. The designation "forceps" is not an appropriate one for the 

 posterior lobes of the fifth sternite, since these lobes are not forcipate; 

 and the true genital forceps are appendages of the ninth, not the 

 fifth segment. On this account, it is preferable to refer to the struc- 

 tures in question simply as tlie posterior lobes or processes of the 

 fifth sternite. 



