300 Mr. W. Wcscli6's Notc>i on the valve of 



From this it can be seen that the prcsuniptiou of close 

 relationship suggested by the nunith is contradicted by 

 the character of the male genitalia, and the venation only 

 proves a family relationship. But when the extraordinary 

 changes in the ovaries of the female of G. paljialis, Des., 

 shown in Prof. E. A. Minchin's paper,* Stoinori/s remain- 

 ing normal, are taken into consideration, together with 

 many other points of structure external and internal, it 

 is clear that Glossina and Stomo.iys are far removed from 

 each other. 



A comparison of the Muscid species bearing specialised 

 trophi, Dryniia, Stomoxys, Hminatohia, Lyperosa, Froscna, 

 Sipliona, Glossina and Mady.za (the details of the argu- 

 ment are too long to (piote here), has led me to the 

 conclusion that these specialised mouths, like those of the 

 genera already (pioted, arc cases of parallel development. 



The genital affinities between Tijmla, Seatopse, the 

 Stratiomyid genera, Asihis, Bolichojms and the Empidse 

 are supported by a similarity which is also a peculiarity, 

 in the anatomy of the mouth. In families in which the 

 mandibles arc aborted, they are embedded in the labium. 



(1) In the Tipulicke it can be demonstrated that they are 

 in the ventral side, as the lever on the dorsal side sends out 

 processes to which the palpi are attached, which shows 

 that they arc the fused cardincs and stipites of the 

 maxilke. 



(2) In Buliclwpas there is a marked thickening of the 

 mentura on the median line and a structure .showing the 

 presence of atrophied or aborted organs. In the related 

 Ajjhrosylns raptor, Hal., the mentum is simple and 

 without this structure, but two chitinous blades can be 

 dissected out of the muscles underneath it. 



(3) In the Empidie, Stratiomyida; and Seatoptsc this 

 character of a thickening of the chitin of the mentum on 

 the median line is very marked. 



(4) In the Asilidai the mandibles are present, so the 

 character fails, but the presence in the head of a structure, 

 h(miologous with the pharyngeal pump in Culex and 

 Tipnla, connects it with the Empida' and Dolichopodida3, 

 and so establishes the value of the genitalia character in 

 all these instances. 



The second type of penis, that found in I'tyelioptcra 



* Report on the anatomy of the Tsetse-fl}^ (G'lussina palpalhi) 

 Pior. IJoy. Soc, vol. T(> 1\ I'.X).'). 



