C 260 ) 



Mostly the suliinavgiiiiil .spots of the hindwings are hirger than in idcifioiin, and 

 mtieh more arched ; the sjiot at, the anal angle below is especially large, and often 

 penetrates into the cellule between the upper median nervules. 



The scent-organ within the abdominal fold of the male is of the colour and 

 shape of that of P. alcinoiis; among menciiis occur, however, many sjjecimens in 

 which the abdominal fold is less extended in length and breadth, and hence the 

 woolly iiatch of such specimens is narrower and shorter, and is sometimes reduced 

 to even half the normal breadth ; but what puzzles me much is the occurrence of 

 individuals with the abdominal fold at least a fourth shorter than in ordinary 

 examples of vienciu-s — if we take the forewing = 100, the abdominal fold is about 

 50 in ordinary niencius, and only 38 in the specimens here alluded to — and with 

 the woolly scent-organ whitish grey, not blackish brown ; moreover, the scent-organ , 

 owing to the narrowness of the abdominal fold, is almost of even breadth, which does 

 not reach 3 mm. 



According to the development of the abdominal fold, and the woolly scent-organ 

 within it, I distinguish three forms of the male sex : — 



(1) The abdominal fold and the scent-organ are of the same shape and coloiu" 

 as in P. alcinous Klug ; there occur, however, many specimens which have the 

 abdominal fold reduced in length and breadth, and the woolly patch shorter and 

 narrower ; sometimes the patch is of only half the normal breadth. This form 

 agrees better with alcinoun Klug than the following ones, but is not typical niencius 

 Feld. ; I call it confusus. To confasus, not to alcinous, belong the Loo Choo specimens. 



(2) The abdominal fold is reduced; the woolly patch is not blackish brown, but 

 greyish white. Forewings rather paler than in the preceding form. Gray's tigme 

 represents this insect ; in the Felderian collection and in the Britisli Museum are 

 sjiecimens of this variation onlv, so that we must take it for typical niencius Feld. 



(3) The abdominal ibid much more reduced than in typical mencius, at least 

 a fourth shorter than in (1) ; if we take the forewing = 100, the abdominal fold has 

 a length of about 50 in (1), and of 38 in the present form. The woolly scent-organ 

 is whitish, as in mencius, but, owing to tlie narrowness of the abdominal fold, much 

 narrower and of almost even breadth, which does not reach 3 mm. This insect I name 

 impediens ; the type came from Ta-tsien-lu. 



In order to come to a satisfactory result about the specific distinctness or non- 

 distinctness of these three easily recognisable forms (mencius, confusiiji, impediens), 

 which are, to my knowledge, not connected with one another by every intergradatiou, 

 we have examined the sexual organs of the males of alcinoiis, of the three 

 supposed forms of mencius, and of plutonius. As I already knew from other 

 \ariable species that it is quite insufficient to examine one specimen only of every 

 form, a great number of individuals of these insects have been dissected, and the 

 reader will learn, with the help of Plate VI. : — 



(1) That the .sexual organs of the nude, e.specially the " harpe," * are inconstant . 

 if one compares a larg. r number of sjiecimens of a varialile species (see tigs. 1-11, 

 12-20, 21-25, 27-30); 



(2) That on the whole the black-headed (.lapanese) alcinous Klug is different 

 in the sexual organs from the red-headed (Chinese) confusns m. (see tigs. 1-11, 

 13-20); but that there occur individuals of aldnous whicli have the organs in 



* For the s:ikc of convenience I have ailupted the s:inie names for the organs as Mr. tJosse in his 

 paper on the clasping-ovgans ancillary to i;eneralion in certain {groups of Lepidoptcra (TV. Linti. Svc. Lmd- 

 (2). Zool. IT. p. 2(;r) (1883). 



