40 



INTRODUCTION. 



compressed club, which is rather abruptly inflected or bent outwards. This form 

 is exhibited in PL ii, fig. 4, c. PL iv, fig. 1, c. % c. and PL i, fig. 1, 2. 



The anterior "dings are generally regular along the posterior margin, which is 

 either straight or slightly curved. The posterior wings are entire, dentated, or pro- 

 vided with one or more tails, the peculiar character of which consists in being 

 slender and linear ; in several genera the tails afford a very beautiful decoration. 



The feet are slender, long, perfect in all parts, and alike in both sexes : the ante- 

 rior feet are never spurious, and although in one section of the genus Thecla, they 

 are somewhat shortened, yet all the parts are perfect. This partial abbreviation is 

 observed in Fam. M. of W. V. Larva oblongoscutata, where the imago is described : 

 " pedibas duobus anticis aliqaanto minoribus." The anterior feet are without any ap- 

 pendage, but the intermediate pair have on the thighs, in all genera as far as I have 

 observed, a short acute process, about the middle. The tarsi are small. The pecu- 

 liarities will be stated in the generic characters. The body is, on the whole, small, 

 slender, and compressed ; the proboscis either short or moderately elongated, and in 

 general provided with erect bristles towards the extremity. 



The second stirps, which from the character it exhibits in the first stage of its 

 existence, is denominated Chilognathiform or Juliform, is the principal of the whole 

 tribe, and the larva is typical of the whole order of Lepidoptera. This has already 

 been stated in the general remarks on the analogical relations, between the metamor- 

 phosis of the Papilionida; and the class of Ametabola, where it appeared that the 

 Juliform habit of the larva of this order had already been pointed out in the Horae 

 Entomologicag. I therefore proceed at once to the description. The larva of this 

 stirps is generally characterized by smoothness of surface, cylindrical shape, and 

 great length of body : but it presents the following modifications of form, in 

 tracing which I shall commence at the confines of the Vermiform stirps ; here we find 

 it attenuated at both ends and transversely striated ; an example is given in the third 

 plate in fig. 14, belonging to the genus Colias, which, if my conclusions are correct, 

 determines the natural situation of this genus. Hence we pass, assisted by various 

 corresponding indications, in the other stages of the metamorphosis, to a regularly 

 cylindrical larva, in which the transverse strias are more obscure, and which is slightly 

 hairy and marked with numerous small dots, uniformly disposed along the sides of the 

 body. This group embraces the genera Pieris, Pontia, &c. In the typical groups, 

 which follow next in order, the larva has a swelling or distension about the fourth or fifth 

 segment of the body, from which it tapers more abruptly to the head, and in a gradual 

 manner towards the anal extremity. This typical group consists of the true Papi- 

 liones as more rigorously defined and arranged in the genus Papilio, exhibiting, how- 

 ever, several modifications of form, which will be pointed out in the sequel as types 



for 



