ISl" Mr. Swainson oti ike Natural Affinities 



perfections of the diurnal Lepidoptera, the superiority would 

 undoubtedly be conferred upon this group, did they not show 

 a decided inferiority to the last in their imperfect construction. 

 The anterior legs are destitute of claws, and are so short, as 

 to appear at first sight perfectly useless. The angular form 

 of the pupa is still fully preserved ; yet, instead of being braced, 

 it is suspended only by the posterior extremity. The lower 

 wings of the perfect insect are dilated, so as to form a groove 

 for the defence and support of the short conic body. It is 

 obvious that this particular construction is admirably adapted 

 for giving to these insects that superiority of flight for which 

 they are remarkable. Yet in this power there are gradations : 

 it is most developed in the genus Paphia, F., but is diminished 

 in MorpJw ; the former is conspicuous for strength, the latter 

 for size and beauty. Tracing this gradation further, we find 

 in the genus Hipparchia a feeble and irregular flight, and 

 a considerable falling off", in other respects, from the typical 

 characters. 



The following observation of the celebrated Latreille de- 

 serves particular attention, in this part of our inquiry. ^^ Papll. 

 Crameri: Phlegia, Etigenia, Calliope, Eutcipc, Diaphana, 

 Lenea, Nise, Melanida, etc.; Heliconiorum habitus; horum 

 lepidopterorum sedes naturalis incerta ; an genus proprium ? " 

 No better authority can be brought forward to show that we 

 have now arrived on the confines of another and a very ex- 

 tensive group, typically represented by the genera MecJiaiiitis 

 and Idea of Fabi'icius : these, with Euplcsa, and probably 

 Acra'a of the same author, are marked by the same debility 

 in their anterior feet, and the same mode of suspension in their 

 pupa state, as the last : the pupa, however, is obtuse, and quite 

 smooth ; while the perfect insect, from its delicate consti'uction, 

 betrays a weakness of flight unexampled among the diurnal 

 Lepidoptera. This I have myself witnessed. The feeble tex- 

 ture, and horizontally lengthened wings o'l Mechanitis seem, 

 during flight, scarcely sufficient to support its long and clavate 

 body. As we recede from these, the anterior i'eet in one or 

 two groups, not hitherto characterized, begin to assume a more 

 decided form, as if Nature was about to (juit this tyjie for an- 

 other. Unfortunately, the slight information we possess on 

 the metamorphosis of these insects, leaves me in much igno- 

 ance in this part of my inquiry ; and I must content myself 

 with noticing the generally weak construction, and striking 

 similitude between several of the Heliconi and Erycina: of 

 Latreille, as circumstances strongly in favour of a natural affi- 

 nity. 



The next division comprises groups of the most singular 



and 



