106 THE entomologist's record. 



the RJiodocerinae, we find only the 5th segment movable, whilst in 

 EucMoe the pupa is solid and immovable. 



There is, I think, something to be said from a larval, and even from 

 an iraaginal point of view, in favour of the notion suggested by the 

 pupa3, that there is at least as great a gap between Aporia and Pieris, 

 as between the latter and the RJiodocerinae. 



The third line of development from the primeval, Papilio-like form, 

 is in the direction of the Lyc£enids. Here my material is so scanty 

 that I have found very little trace of intermediate forms. There is, 

 however, I think, much to be said for the possibility of the Lycasnids 

 having been derived from the Hesperids, merely grazing, as it were, 

 the Papilionids on the way. 



The Lyca^nids at least acquired the same method of pupal suspension 

 as the Papilionids ; and further, they lost the " Micro " habit of the 

 Hesperids of hybernating as larvae, and acquired the habit of doing so 

 in the egg or pupa-stage ; the egg, likewise, is much farther from a 

 Hesperid egg than is that of a Papilionid. Parnassius, at first a very 

 puzzling form, comes in here to give us some little assistance. Its pupa 

 is very much like that of the LycEenids, from which it differs chiefly in 

 lying free in a cocoon, instead of being suspended by a girth ; this con- 

 dition is, however, attained by not a few Lyca^nids. The egg possesses 

 certain Lyca^nid features, in particular the depression at the top around 

 the micropyle ; hybernation also takes place in the egg-stage, a 

 circumstance very rare in butterflies, except amongst the Lyctenids ; 

 but I have ascertained that in Parnassius the young larva is developed 

 in the autumn, and passes the winter coiled up within the egg-shell. 



The Parnassids are a small family and, so far as we know, did not 

 develop such a variety of forms as the parallel Lycainids. Partly, 

 probably, for this reason, and partly because Thais, although apparently 

 a Parnassid, is more nearly a Papilionid they have usually been left 

 among the Papilioninae. The few forms we have, however, to judge 

 from the pupa? which I have been able to examine, are in reality rather 

 widely separated from each other, and suggest that they are only the 

 remains of a much larger family, of which tlie intermediate forms have been 

 lost. A few words upon the several forms ma}^ therefore be interesting. 



1. Thais (figs. 3-4-5). — Here the head spines of Papilio are either lost 

 or modified into the double central knob which carries the hooks. The 

 front of the pupa is curiously flattened and hollowed, by the falling in 

 of the pro-thorax and front of the meso-thorax. It is to be noted, eitlier 

 as showing that Thais is rather a Papilionid than a Parnassid, or as 

 showing the line of Parnassid evolution, that a genus usually left with 

 Papilio, containing some half-dozen species, of which dissimilis is perhaps 

 the best known, has a very similar form to Thais, though its suspension 

 is of the orthodox Papilionid type. 



2. Sericiniis. — Here tlie form and structure are very similar to Thais ; 

 but, while the cremastral hooks are lost, the double nose-horns of Pa- 

 pilio are retained ; both the 5th and 6th abdominal segments are still 

 free ; and the dorsal spines of Papilio, duplicated on 5, 6 and 9, are 

 present ; the egg is quite Papilionid. 



3. Luehdorjia. — In this, we still find suspension in Papilionid-fashion, 

 and the pro-thoracic spiracles have the same })it-like aspect as in Thais 

 and Sericinns, but the general form is now squat (like that of Parnassius) 

 the surface rough as in Doritis, and there is movement only at the 4th 

 abdominal incision ; the nose-horns are still quite distinct. 



