( liii ) 



of appendages, the Sagittae, which are connected together 

 by a membrane, the Spatha, and the Sagittae + the Spatha 

 function as a penis. 



" The Sagittae often have serrated edges which probably 

 serve to hold them in position during copulation. 



" The three pairs of appendages which make up the External 

 and Internal Paramera enclose each other. 



" The Suhgenital Lamina is a plate situated beneath the 

 genitalia, and consists of the 9th ventral segment of the 

 abdomen. It is sometimes pointed, forked, or rounded, and 

 presents valuable distinctive characters in some genera. 



" Finally, we have a small pair of hairy appendages, the 

 Penicilli, M'hich are attached to the 10th dorsal segment of 

 the abdomen. They are not present in some genera such 

 as Anergates, Dorylus, etc., and in Prenolepis they are present 

 in some species and wanting in others, and are consequently 

 valuable for classification purposes. 



" They are stated to represent the Cerci in Blatta, etc., but 

 this does not seem to be absolutely certain." 



Mr. Donisthorpe then described the structure of the abdo- 

 men in ants showing that the 9th and 10th dorsal segments 

 in the cJ were rudimentary and situated beneath the last 

 visible abdominal segment — the pygidium, and that the last 

 ventral segment was the 9th — the 10th being lost, and was 

 situated beneath the 8th ventral segment — the hypopygium. 



Mr. Donisthorpe then explained the Historical Chart. He 

 pointed out that he had practically followed Prof. Emery, 

 who had made a careful study of the whole subject in 1895. 

 Although in the 1895 paper Emery refers to the sagittae as 

 the " Innere Parameren," in his later works he uses the term 

 " Sagittae." 



Genital Armature op Aculeate Hymenoptera.— The 

 Rev. F. D. MoRiCE exhibited a series of Lantern-slides to 

 show the structure of the cj genital armature and the ventral 

 segments adjoining it in various groups of Aculeate Hymeno- 

 ptera, and more particularly the characters exhibited by 

 two of these segments (the 7th and 8th) in 35 Palaearctic 

 species of the Genus Hylaeus, F. {Prosopis of Jurine and 

 most recent authors). 



