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XVII. On the Male Genital Armature in the European Khopalocera. By 

 P. Buchanan White, M.D., F.L.S., fyc. 



(Plates LV.-LVII.) 



Eead December 21st, 1876. 



JN several orders of the Insecta the structure of the organs upon which the perpetua- 

 tion of the species depends has afforded in very many cases the best and surest cha- 

 racters for the discrimination of species. But in the Lepidoptera, one of the largest 

 of the orders, and that on which perhaps the greatest amount of attention (scientific or 

 otherwise) has been bestowed, the structure of these parts has not only not received 

 the consideration it deserves, but has been almost entirely ignored *. Moreover those 

 lepidopterologists who have not altogether neglected to examine this structure have been 

 of opinion that it affords generic rather than specific distinctions. 



With this opinion, however, my observations prevent me agreeing ; for I think that 

 not only generic, but, in many (if not in every) species, good specific characters are to be 

 found ; and to show that this is the case is my object in laying before the Society the 

 following notes. 



In them I have confined myself to the European Bhopalocera. Whether every family 

 of the Lepidoptera will show equally good characters my researches have not yet been 

 extensive enough to enable me to decide ; but from what I have seen I am inclined to 

 think they will. The distinctive characters do not always lie in the same parts, nor are 

 they equally perspicuous in every group ; but in one part or other, if not in all, some 

 distinctive character is to be found, and, allowing so much for individual variation, the 

 difference of structure is constant and appreciable. 



An examination of the hind body of a male Trichopteron will show that it is furnished 

 with certain corneous appendages, protruding from the interior of the apical segment, 

 which appendages have been termed the " appendices anales." Of these there are 

 normally three pairs — the appendices superiores, inferiores, and intermedia?. 



If the hind body of a male Lepidopteron is denuded of the scales and hairs with which 

 it is clothed, somewhat similar appendages (more or less covered externally with scales 

 and hairs) will be seen protruding, to a greater or less extent, from the orifice of the 

 seventh or apical segment (PI. LV. figs. 2 & 3). In many cases the appendages protrude 

 far enough to permit of a good view of their form ; but frequently it is necessary to 

 remove part of the apparent apical (7th), and occasionally of the penultimate (6th) or 

 even of the antepenultimate (5th) segment, before they can be properly seen. 



On making the necessary dissection the appendages will be found to be three in 



* A notable exception is afforded by Mr. S. H. Scudder's various Memoirs on the Hesperidse of North America 

 (' Proceedings ' and ' Memoirs ' of the Boston Soc. of Nat. Hist. &c). 



SECOND SERIES. — ZOOLOGY, VOL. I. 3 C 



