( 492 ) 



bnckle (i), Which is a chitinised portion of the membrane itself, and does not protrude 

 free ; its ventral and lateral ed^es form a sliglitly raised ridge, as can be seen in 

 f 156. The ventral part of this Inu-kle is produced into two processes («), which 

 are thin in a dorso-ventral sense, but divided longitudinally into a left and a right 

 half, which stand at a blunt angle to one another in consequence of the middle line 

 of the process being more dorsal than the lateral edges. At the base each pro- 

 cess is constricted (f. 158), while the edge of the apical half is armed with teeth. 

 In a side view the process (f. 156 and 159) ajipcars plainly as a dilatation of 

 the bnckle b. The vagina v (f. 159) is behind the middle of the median jjiece of 

 the buckle, and marked in f. 157 behind the two processes as a black spot. 



The scries oi ffinalen examined has not been very great, and hence we do not yet 

 know whether there is not some variation in the form of the armature in the various 

 subspecies. From what we have seen we must conclude that if there is such a varia- 

 tion it must be very slight, as neither the European and Asiatic nor some American 

 forms of P. machaon presented any obvious deviation from what we have figured on 

 PI. XIX. And this would be entirely in accordance with what we have found in the 

 /««7f' genital armature of /««f/<aow, asfar as a distinction between the genital armature 

 of the various subspecies of this species goes. We can safely say that in P. machaon 

 from Europe and Asia — 



(1) There is no character iu the genital armature of botli sexes of any of 



the subspecies by which the greater percentage of the individuals 

 could be distinguished ; 



(2) There are obvious characters in the colour and pattern of the wing 



and body of each subspecies by which the greater percentage of the 

 individuals, but not every specimen, can be distinguished. 

 The genital armature of P. xuthuA is entirely different from that of machaon.* 



17. Papilio polytes; f. 160 and 161. 



lYiQ female of this species is polymorjihic; we have examined the three female 

 forms from Ceylon and North India, the two forms from Borneo, the three from 

 the Philijijiine Islands, and also a single specimen of each of the subspecies from 

 Celebes, Saugir, Sulla Islands, Amboina, and Halmaheira. 



There is a good deal of individual variation in the apjjaratus of P. jjoli/tes, but 

 this variation is entirely indejieiulent of the colour and jiattern of the wings, and 

 hence the various forms oiiVi' female of each subspecies must be pronounced to be 

 identical in the genital armature ; ?-f. romulm, ?-f ci/rxs, and ^ -L pohjles do not 

 ])resent any character iu the vaginal armature by which one form is distinguished 

 from tlie otiier, and so it is with ? -f. theseus and ?-f. viriUs, and so on. 



The intersegmental membrane (f. 160) is just underneath the eighth segment 

 at each side thickened and corrugated, the corrugated jjortion having an elongate- 

 ovate outline ; round the orifice of the vagina there is a low ridge continued 

 ujjwards to the hinder end of the corrugate mark ; this ridge is raised into five 

 processes, one ventral and two on each side lateral. The form of the processes is 

 visible in f. 161, which represents the apparatus flattened out and viewed from the 

 anal side ; the ventral process is rounded, the lateral ones are sharjily pointed, 

 the lower one is the longest. The length of the lateral processes is variable. 

 Above the vagina there is a rounded tubercle, t, present in all allies. 



• This confirms Dr. Scitz's opinion that xidhus is not a very near relation of machaon. See Soc. Eat., 

 18a.">. p. 130. 



