168 Mr. J. O. Westwood on the Oriental Species 



Ingenious however as these views unquestionably are, and dis- 

 satisfied as I have expressed myself to be with the various classi- 

 fications of the tetrapod butterflies hitherto proposed, I am by no 

 means satisfied of the propriety of regarding the Hi pjjarchiide^ and 

 Morphidce as together constituting one primary section of the 

 Diurnal Lepidoptera, the very minute analysis of the genera of 

 which, required for the elaboration of the " Genera of Diurnal Lepi- 

 doptera" having proved that the great group Hipparchiidce is a very 

 characteristic one in itself. Much less am 1 disposed to follow Dr. 

 Horsfield in admitting such genera as Apatura, Nyniphalis, Pro- 

 togonius and Paphia into the section having the Hipparchiidcs as 

 their chief type, on account of the cornuted head and bifid tail of 

 the larvae, whilst the general structure of the perfect insect is 

 pre-eminently Nymphalideous. Mr. Swainson appears to have 

 been fully alive to the difficulty of this question, attempting to 

 solve it on the jmnciple of variation in groups. The student, he 

 says, must not believe that all the Thysanuriform larvae, for 

 instance, go into one division. True it is that by such an arrange- 

 ment he would get a uniformity of the same shaped caterpillars, 

 and he might flatter himself with having discovered the true ar- 

 rangement of the Lepidoptera, but when he looked to the butterflies 

 which proceeded from his Thysanuriform larvae he would find 

 that so far from exhibiting that regularity and affinity with each 

 other, which, from looking only at their caterpillars, he had ex- 

 pected, he will be perfectly disappointed. He then points out 

 five'different instances, in which five different caterpillars, answer- 

 ing to the definition of Thysanuriform larvae, produce butterflies 

 which belong to the five primary divisions of the Diurnq, instancing 

 as one of these, which from the length of the horns o^ the cater- 

 pillar might be considered pre-eminently typical, the purple 

 emperor butterfly, which, as indicated above, is given by Dr. Hors- 

 field as one of the primary types of the TItysanuromorpha. The 

 principle of variation on which Mr. Swainson endeavoured to ex- 

 plain this apparent difficulty was stated to be, theoretically, as fol- 

 lows : "every natural group of l)utterflies, either in the caterpillar 

 or perfect state, contains representations of the primary types of 

 larvae, modified however in such a manner as to indicate the real 

 type to which they actually belong" — hence some J uli form butterflies 

 assume the aspect and character of Scolopendriform larvae, others 

 have the Thysanuriform shape, so that, although the butterflies 

 which stand at the head of the Juliform division, as being typical, 

 have Juliform larvjE, " yet that the group, taken as a whole, will 

 contain analogical representations of all the other [four] types of 

 larvae we have described. The Scolopendriform butterflies (Nyrn- 



