( 491 ) 



fompiiir the jKisiridii and (lircutiou and the outline of the homologous ])arts ut' the 

 apparatus of the allied insects, and thus to be able to observe minute differences in 

 the most nearly related forms. As in live specimens, or in individuals sliortly after 

 death, a pressure of the abdomen sufficed to bring the organs in question fully in view, 

 it was e^ndent that a method of preparation of dried specimens would be successful, 

 if the intersegmental membranes of the eud of the abdomen were so relaxed that the 

 whole apparatus conld be jiushed out without destroying tlie connection between the 

 several organs. The method of jireparation we employ is quite sufficient for our 

 purpose, and has the great advantage of being very simple. We cut off the last four 

 segments, soak them in hot alcohol and water, remove the eggs, scales, etc., with the 

 help of a pin and brush, press the segments gently, and leave the abdomen in alcohol 

 and water until the segments are freely moveable ; then we ])ress the head of a pin 

 from the inside of the abdomen against the vaginal bulb, and push it gently out, 

 taking care that tlie meniliranes do not get torn. The eggs an<l tlie hursii cojniliitfix 

 onght to be preserved. 



While in a live specimen the membraneous and the more chitiuised parts in the 

 vaginal region are easily distinguished by their colour, in a dry individual all the 

 parts are more or less brown, and, though the strongly chitinised organs are recog- 

 nisable by their gloss, the exact limits between the membrane and the chitinised 

 pieces which it connects are often obscured. 



According to the development of the eighth segment the Eastern Papilios can 

 be divided into two groups — such in which the eighth segment forms a complete 

 ring without longitudinal sutures (f. 182), and snch in which the ventral plate is 

 absent. To the first group belong nearly all those Indian and African species exa- 

 mined in which the first subcostal nervule of the forewing anastomoses witli the 

 costa, except P. mandariniis and allies, and to the second group all the other Papilios 

 examined, inclusive of Troides = Ornithoptem. The combination of an obvious 

 character in neuration with a still more conspicuous particularity in the development 

 of the eighth abdominal segment of ihe females of the species allied to agamemnon. 

 sarpedon, codriis, ciristeus, and imtiphutes of the Indo-Australian Region, and of 

 antheus, leonidas, pijlades, etc., from Africa, indicates certainly more than mere 

 similarity in form. 



The special copulatory apparatus consists of processes, ridges, tubercles, an<l 

 folds near the vaginal orifice, all more or less chitinised, often dentate and hook- 

 shaped. It is not a modification of the ventral plate of the eighth segment, but is an 

 independent structure of the intersegmental membrane. The variety of the apparatus 

 in the various species is startling, as a glance at f. 156 to 182 will show. Tiie 

 orifice of the vagina, marked '■ in the figures on PL XIX., has in the diverse grou])s 

 of I'apiUo a difierent position ; in I'. (ilelnouH, pliiloxeiius, and allies, it has a 

 ventral (j-ecte basal or anterior) (f. 179), in podalirius and allies (f. ISl) a more 

 dorsal (recfe apical or posterior) position. 



The variability of the copulatory apparatus we explain by figures only of four 

 species ; this must suffice for the present. P)Ut to demonstrate |the classificatory 

 value of the armature we give figures of seven more species. 



10. Papilio machaon: f. l">r, tci ]."i',i. 

 The figures are taken from a British individual. W'licn examining the inter- 

 segmental membrane which l)ears the orifice of the vagina and the chitinised prc- 

 liensile ajiimi-atus we perceive (f. 157) a somewhat lyriform or horseshoe-shaj)e(l 



