Xo. 64] DIPTERA OF CONNECTICUT: MORPHOLOGY 91 



of the ninth segment (and proctiger) occurs in male mosquitoes. As 

 Edwards points out, this inversion takes place within a few hours 

 after the male mosquito emerges from the pupal stage, as the result 

 of a rotation of the parts about the long axis of the body, through 180 

 degrees. As the result of the inversion, the ninth sternite, for exam- 

 ple, now becomes dorsal in position, and the ninth tergite becomes 

 ventral in position, but the tergite and sternite are still referred to as 

 such, despite their displacement. 



The ninth segment may form a more or less continuous sclerotized 

 ring in male culicids, but the ninth tergite (A^hich is secondarily^ ven- 

 tral in position) is usually demarked from the ninth sternite (which 

 is secondarily dorsal in position) by slight constrictions, or by faint 

 sutures, etc. The ninth tergite may bear a pair of tergal lobes, 

 labelled tl in Fig. 11, A, which are called setaceous lobes by Felt 

 (1905), or the basal appendages by Howard, Dyar and Knab (1912) ; 

 and these structures are of some value in classification. The ninth 

 sternite usually exhibits fewer modifications of taxonomic value than 

 the ninth tergite does. 



The genital forceps or forcipate parameres are composed of two 

 segments, namely a basal segment, cxi, called the "basistyle" or basi- 

 mere, and a distal segment, st, called the "dististyle", or distimere. 

 The distal segment of the forceps, st, bears a terminal claw-like ap- 

 pendage, labelled da in Fig. 11, A, which may represent a modified 

 second segment of the distimere or dististyle. 



The basal segment of the genital forceps, labelled cxl in Fig. 

 11, A, is called the coxite by de Meijere (1919), the basistyle by 

 Crampton (1923), the gonostipes by Cole (1927), the "side piece" by 

 Dyar and Knab (1909), the basal clasp segment by Felt (1905), 

 the basal joint of the superior clasper b^; Newstead (1911), the basal 

 lobe by Nuttall and Shipley (1901), the pleurum by Snodgrass (1904), 

 the coxopodite by Snodgrass (1935), and the harpagoger in recent 

 papers. 



The distal segment or clasper of the genital forceps, labelled 

 st in Fig. 11, A, is called the stylus by de Meijere (1919), the disti- 

 style by Crampton (1923), the clasp filament by Howard, Dyar and 

 Knab (1912), the terminal clasp segment by Felt (1905), the clasper 

 by Nuttall and Shipley (1903), the apical appendage by Snodgrass 

 (1904), the stylus by "Snodgrass (1935), and the harpago in recent 

 publications. The designation harpe is also applied to this structure 

 by some entomologists. 



The lobes labelled alh and hal in Fig. 11, A, are called the apical 

 and basal lobes (of the basimere or "basistjde"), and the U-shaped 

 folds, ibf, are called the interbasal folds by Freeborn (1924), while 

 their processes, cp, called the claspettes by Edwards (1920), corre- 

 spond to the structures called the "harpagones" by Howard, Dyar 

 and Knab (1912), or to those called the harpes (in part) by Felt 

 (1905). The designations harpes and harpagones, however, are ap- 

 plied to the distal segments of the genital forceps of other insects, 

 including the nematocerous Diptera, and it is very confusins; to at- 



W. 



