156 MR. J. O. WESTWOOD ON THE LEPIDOPTEROUS 



of the transformations, and especially by the structure of the veins of the wings, feet, 

 antenna*, palpi, tongue, and other characters of the imago, we have arrived at certain 

 results as to the characters of certain groups which had formerly been comparatively only 

 partially examined ; yet the want of a general revision of all the groups of the Order in 

 the same philosophical manner, has still left us in doubt as to the proper clue to the clas- 

 sification and relations of the families and still higher primary divisions of the Order. 

 I do not hesitate to say that the attempts to characterize and systematize the families 

 and subfamilies of Nocturnal Lepidoptera hitherto made are total failures. 



Another difficulty, unknown to the older writers upon this order of insects, has arisen 

 from the exploration of numerous adjacent localities, which, whilst it has added greatly 

 to our knowledge of new and quite distinct species, has also shown that the wide geo- 

 graphical range of a species is often attended with the development of slightly modified 

 races which have by some writers been indifferently regarded as distinct species, or have 

 been sunk to the rank of local varieties. Thus, of the gigantic types of the diurnal 

 Lepidoptera which, from their size, have been well named Omithopterus, and which are 

 natives of the East, we find the single species, Papilio JPriamas, in Mr. Kirby's Cata- 

 logue, made to comprise not fewer than seventeen of these local forms. These have been 

 specifically named, and regarded by others as distinct species, namely : — 1. P. Pri- 

 amus, Linn.; 2. Panthous, Linn.; 3. Bichmondia, G. R. Gray; 4. Cassandra, Scott; 

 5. Buphorion, G. R. Gray ; 6. Pronomus, G. R. Gray; 7. Poseidon, Doubleday ; 8. Cronius, 

 Eelder; 9. Boisduvalii, Montrouzier ; 10. Oceanus, Felder; 11. Armaria, Eelder; 

 12. Urvilliana, Guerin; 13. Triton, Eelder ; 14. Pegasus, Eelder ; 15. Archideus, Eelder; 

 16. Lydias, Eelder ; 17. Croesus, Wallace. 



Another series of Eastern Butterflies, of which Papilio Paris is the type, distinguished 

 by having their wings powdered with golden-green atoms, exhibits a number of permanent 

 variations of no higher specific rank than those of the Priamus group in their respective 

 localities ; yet we find each of them, in Mr. Kirby's Catalogue, given as a distinct 



species. 



The solution of this difficulty can only be hoped for by the very careful investigation 

 of such Protean species in their native haunts, with reference to their appearance in the 

 adjacent and intervening localities, so as, if possible, to determine how far the specific 

 type becomes modified (at least, so far as the markings of the wings are concerned) by 

 change of situation and other local circumstances. And here it is to be observed that 

 possibly too much weight has been given to the mere markings of the wings, without 

 sufficient attention to the question whether they are accompanied by structural differ- 

 ences. It was, for instance, with considerable doubt that I at first regarded several of 

 the Heliconiiform species of Castnia described below as specifically distinct ; the inves- 

 tigation of their wing-veins, however, satisfactorily proved that they were structurally 

 different from each other. But paradoxical as it may at first appear, the publication 

 of descriptions of Butterflies and Moths (unless belonging to well-defined and previously 

 characterized genera) has probably become the greatest obstacle in the way to our know- 

 ledge of the real " methodus optima " desiderated by Latreille. I do not hesitate to 

 affirm that the publication of the hundreds, nay, even thousands of careless and insuffi- 



