( 488 ) 



is much more extended than in the two ])receding subspecies ; when seen from 

 above, as in f. 82, it is a kind of half- ring ; f. 83 gives the same organ in a view 

 from the dorsal side of tlie valve. The difference between the ridge of arisfeiis and 

 that of hermocrates and anticrates is obvious enough without further comment. 

 Intergradations in the form of tlie organ are unknown to us. F. 81 to 83 are 

 taken from a Halmaheira individual. 



The subdorsal process is denticnlate, and is longer tlian in Iwrmocratets and 

 anticrates, projecting distinctly beyond the upj)er edge of the ventral lobe of the 

 valve (f. 82). 



d. P. aristeus parmutus from Queensland, New Guinea, and Waigeu. 



This subspecies agrees externally so well witli the Indian /-*. aristeus anticrates 

 that Professor Eimer did not perceive the slight differences in colour and pattern 

 which generally separate parmatus from anticrates, and whit:h Mr. Rothschild 

 ]iointc<l out on ]>. 419 of Vol. II. of this journal. 



Although we know from several sjiecies that in forms wliich in the wiug-colonr 

 and pattern are the most closely allied the genital armature is more different than in 

 externally less closely allied forms, we were nevertheless much surprised to find 

 that aristeus parma.tus has, in opposition to aristeus anticrates, the same genital 

 armature as aristeus aristeus ; we dare say exactly the same, as we hare not founil 

 a simjle character by which the apparatus of parmatus could be distinguished from 

 that of the Moluccan iusect. This discovery is very important, as it shows evidently 

 that, in order to understand the relation of a form, it is necessary to compare sets of 

 entirely independent charai'ters, and as it further proves that a form externally 

 similar to another can be dissimilar in the genital armature, while it agrees in these 

 organs with an externally very different form. 



1-5. Papilio rhesus from Celebes, Saleyer, and Djami)ea; f. 84, 85. 



Though Eimer removes this iusect from aristeus and puts it into another group 

 of sjiccies along with American species, such as ajax, all the characters l)y which 

 P. rhesus is distinguished from P. aristeus are developments of the cliaracters of 

 aristeus. The only argument in favour of a relationship with ajax is the number 

 of the black bands on the forewiug ; in rhesus there is one band less than in 

 aristeus ; but even this argument is not valid, as there very often occur specimens 

 in which the usually absent band is indicated by a black spot, and as tlicrc are even 

 examjilcs in which this sjjot has developed to a distinct band. All the other 

 characters of the wing-pattern speak against a relationship with ajax, and this 

 statement is corroborated by the moridiology of the male sexnal armature and \t\ the 

 form of the eighth abdominal segment of the female. To begin with the latter, it 

 will be sufficient to say that the eighth segment in rhesus is complete, as in aristeus, 

 agamemiwii, .sarpcdon, etc. (see f. 182, sarpedon sarpedon ; f. 185, aristeus 

 pai-matus; f. 187, mac/arlanei) ; whereas in ajax j the eighth segment is 

 incomplete, as in f. 181 (podaliriu.s). The similarity in the armature of the valve 

 <if rhesus with that of aristeiM will become evident by comjiarini;- f. 84 and 85 

 with 75 and 8;!. 



The dorsal lobe of the valve of rhesus (f. 84j is much broader than even in the 

 Indian aristeus anticrates, except the free apex, which is comparatively narrower; 

 the subdorsal process is thin, ioul. as in anticrate.t, not dentate ; fli(> ventral ridge 



