1030 THE BUTTERFLIES OF NEW ENGLAND. 



has been given hitherto the reasons for placing it in a position next to the 

 lowest butterflies. This lias already been done in part in the Introduction 

 to this work (pp. 70-75), where, in discussing the classification of" but- 

 terflies, we have pointed out that two series could Ije followed throughout 

 the entire range of butterflies, in which there was an evident progression 

 in structure and in life between those groups which are here regarded as 

 the lowest and those regarded as the highest, — series which were com- 

 pletely parallel to each other and which could be offset by no similar series 

 following any order whatsoever. These points concern the structure of 

 the fore legs and the mode of suspension of the chrysalis, and need not be 

 repeated here. 



It is not essential to the argumnnt to consider the two groups, Pierinae 

 and Papilioninae, equal subordinates in one family, Papilionidac, since 

 whether they are regarded as subfamilies or as independent families of 

 equal taxonomic value with the other family groups discussed in this work, 

 they have been universally considered by all naturalists up to the present 

 time as directly akin to each other, and the relationship has been so evi- 

 dent that it has not been deemed necessary to insist upon it. The quad- 

 rate structure of the front of the head, the insertion of the antennae, the 

 relation of the metathoi'ax to the mesothorax, the complete development 

 of the front legs of both sexes, the special development of the dorsal 

 margin of the eighth abdominal segment of the male, the structure of the 

 abdominal appendages of the same sex, the general structure of the young 

 caterpillar with its relatively small head and its armature of apically ex- 

 panding bristles, the similar structure and form of the mature caterpillar 

 with its relatively smooth head and spineless body, and the precisely simi- 

 lar mode of suspension in the chrysalis, all show that the uniform opinion 

 of naturalists in past time is entirely just. The arguments, however, 

 which have been used in support of the high rank of these insects, have 

 been drawn altogether from structures found in the Papilioninae only ; it 

 is not a little singular that not a single one of these characteristics is found 

 in the Pierinae, and as we have already pointed out in the Introduction, 

 every one of the points considered of high importance is most unfortu- 

 nately chosen, as each can be jiaralleled in the lower groups and some are 

 features peculiar among butterflies, not to the Papilioninae alone but to 

 the Papilionidae and Hesperidae, and are plain indications of that aflinity 

 for the lowest family which is marked in so many different ways. Hence 

 in the following brief review of other points of agreement between the 

 Papilionidae and Hesperidae some of which are here noticed for the first 

 time, we shall draw entirely upon the structure of the Papilioninae. 



If one compares the structure of the compound eyes in the entire series 

 of butterflli's, he will be struck by the curious fact that there is great dif- 

 ference between tlK>m in the extent of the cornea over the globular field. 



