No. 64] DIPTERA OF CONNECTICUT: MORPHOLOGY 103 



of the abdomen merge with the metathorax in the Diptera, and con- 

 sequently oives a higher number to each of the segments than it 

 should have, which makes it very difficult to understand his state- 

 ments concerning the nature of the individual segments in the Syr- 

 phidae, in his extremely important paper on the syrphid. terminalia. 

 Balfour-Browne (1932) reverts to Berlese's old view that the 

 parts revolve in a counter-clockwise direction in the Sja-phidae, and 

 consequently interprets the displaced sternites as "tergites" in his 

 figures of the postabdomen of Eristalis. Balfour-Browne likewise 

 follows Berlese in giving a higher number to each of the segments 

 than it should have, which makes it very difficult to follow his state- 

 ments concerning the nature of the individual segments of the post- 

 abdomen of the Diptera figiired by him, but if the segments are given 

 their correct numbers in his figures of the postabdomen of Enstalls 

 and Calliphora^ it is apparent that in deriving the calliphorid type of 

 postabdomen from that of the syrphids Balfour-Browne concludes 

 that the eighth and ninth segments of the syrphids unite to form the 

 sclerite here interpreted as the ninth segment in a muscoid fly of the 

 Phoi^nia type, instead of considering that the seventh and eighth seg- 

 ments of the Syrphidae unite (as they do in Paragus^ etc.) to form 

 the pregenital composite sclerite (synsternite) in front of the ninth 

 segment of the calliphorid flies. 



Balfour-Browne (1932) and Snodgrass (1935) both agree in in- 

 terpreting the sixth tergite, 6^, of Fig. 10, E. and Fig. 13, E, as the 

 "seventh" tergite in the muscoid flies, and both agree in regarding 

 the sixth sternite, 6^, as the "eighth sternite'' in these flies, although 

 they arrive at the same conclusions from very different lines of rea- 

 soning. Thus Balfour-Browne gives a higher number to all of the 

 abdominal segments than they should have in the blowfly CdlUphora, 

 and consequentl}^ regards the true sixth tergite as the seventh, in this 

 flj^, while Snodgrass states that the true sixth abdominal segment ap- 

 pears to be obliterated in Pollenia, and consequent^ regards the true 

 sixth tergite as the seventh, in this fly. 



Snodgrass (1935) considers that the sixth sternite, 6s, of Fig. 

 10, E, and Fig. 13, E, is the "eighth" sternite in such a calliphorid fly 

 as Polle/ua (see Fig. 13, E) because it is attached to the composite 

 sclerite bearing the label "iS -f- 8s in Fig. 13, E, etc., which he inter- 

 prets as the eighth tergite in Pollenm, while Balfour-Browne inter- 

 prets the sixth sternite, 6s, of Fig. 13, E, as the "eighth" sternite in 

 Calliphora because he gives a higher number to all of the segments 

 than they should have, in the abdomen of the Diptera in general; 

 and neither of these investigators has suggested the possibility of an 

 inversion of the true eighth sternite in the muscoid Diptera. Cole 

 (1927) likewise interprets the sixth sternite, 6s, as the "eighth" ster- 

 nite in Hylemyia (Fig. 13, D) and considers that the inverted eighth 

 sternite is the ei^ghth "tergite" in such flies as Tetanops aldrichi, etc. 

 Awati (1915), on the other hand, interprets the sixth sternite, 6s of 

 Fig. 13, E, as the "seventh" sternite in the muscoid flies, while Ber- 

 lese (1909J interprets the sixth sternite, Qs, of Fig. 13, F, as the 



