Carpenter & Hewitt — Genitalia and Larva of the Warble-fli/. 277 



the eighth segment, and, as regards its hinder edge at least, we agree with 

 this opinion. In M. Uneatum the front and hind edges, especially the former, 

 are definitely stiffened, and the intervening area (except for two converging 

 tongue-like outgrowths of the front edge) membranous ; it is thus possible 

 that the seventh, as well as the eighth, sternum may be represented here. 



From the hinder edge of this sternum a pair of blunt, stiff, finger-like 

 processes project backwards in both species, one lying on either side of the 

 penis (figs. 22, 23, 24, 26, 27, 28, 30, Q-. 8). These we consider to be anterior 

 gonapophyses, as Lowne does the corresponding structures in Calliphora, 

 called "hook-processes" by Briiel ('97). The "inferior claspers" of the 

 armature of the Tsetse- flies, Glossina, as described by Newstead ('11), are 

 probably homologous structures, and also the " palpi genitalium " of 

 Wesche ('06).' The bases of these gonapophyses are united with the 

 chitinous edge of the large sternal plate, and are continued into the strong 

 median great apodeme (figs. 22, 26, 30, Ap.) — the "Tragplatte" of Briiel and 

 " inferior apopliysis " of Gordon Hewitt — which runs forwards ventral to 

 the ejaculatory duct. The front end of the apodeme is expanded into a 

 spoon-like process, broader and much deeper in H. Uneatum (figs. 26, 28, 

 30, Ap.) than in H. bovis (figs. 22, 25, Ap.), in which the sclerite tapers to a 

 down-curved apex, as viewed laterally (fig. 22). The apodeme is also con- 

 tinuous with the theea or sheath of the penis (figs. 22, 23, 26, 27, 28, 30, Th.), 

 which may be regarded as belonging to the ninth (genital) sternum, to which 

 Briiel would refer also the great apodeme. 



The theca or juxta of the penis is a tubular sclerite surrounding and 

 supporting the membranous glans or vesica (figs. 22, 24, 26, 28, Pe.) which 

 projects beyond it. In S. bovis the theca is continuous all around the base of 

 the organ (fig. 23, Th.) ; but in H. Uneatum there is a narrow median mem- 

 branous area on the ventral aspect. The theca is produced dorsally into a 

 strong median spine (fig. 22, 30, S.) — the "superior apophysis" of 

 Gordon Hewitt in Musea — relatively shorter and stouter than in the Blow-fly 

 tapering slightly to a point just below its forwardly directed tip in H. bovis, but 

 enlarging somewhat in H. Uneatum, until it narrows suddenly close to its sharp 

 extremity. Backwardly the theca extends along the penis in paired lateral 

 processes (figs. 22, 24, 26, 28, 27, 30, Th'), terminating in hooks. These 

 correspond with the harpes described by Newstead in the armature of 

 Glossina. In Hypoderma this part of the apparatus is simpler than in 

 Calliphora, which has two pairs of corresponding processes — the " lateral 

 laminae " of Briiel, and the " hypophallus " and " paraplialli " of Lowne. 



' It is rather disconcerting to the student of these organs to find that almost every one of his 

 predecessors has elaborated a pecnliar terminology of his own. 



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