70 SAMUEL H. SCUDDER. 



• 



small wings, and the presence of a middle pair of spurs on the front 

 and hind legs, in the former developed as a curious foliate epiphysis; 

 their eggs are broadly truncate spheres, sometimes ribbed ; their cater- 

 pillars have a large head, with a very thick skull, a very contracted 

 neck formed of the first body-segment, and bearing a corneous shield 

 above, and a body covered with minute papilkie, bearing microscopic 

 hairs ; their chrysalids are smooth and uniform like the pupae of moths, 

 but in rare instances (e. g. Calpodes*), are pointed in front. 



The other three families appear to have diverged simultaneously 

 from each other shortly after their common separation from the 

 skippers. This latter family is the most homogeneous ; each of 

 the others comprises a considerable variety of structural types, for 

 which it is diflScult, in each case, to find a common expression. The 

 Papilionides however, may be known by the squareness of the head 

 between the eyes, the entire inner margin of the eyes, the diminutive 

 size and frequently lamellar structure of the prothoracic lobes, the 

 acuteness of the front of the nieso-scutcllum, and the notched or 

 produced, instead of entire, dorsal margin of the eighth abdominal 

 segment of the male; in the entire inner margin of the eye, they 

 agree altogether with the Nymphales, but from these they may also 

 be distinguished by the presence, as in the skippers, of a fourth 

 median nervule on the front wing, or by its entire absence; for in the 

 Nymphales it is always transferred to the sub-costal nervure. There 

 are many other particulars in which the sub-fixmilies of Papilionides 

 may be distinguished from all other butterflies, but in which they do 

 not agree together ; the same is also true of the sub-families of the 

 higher groups. 



The eggs of Papilionides, so far as known, are either nearly globular 

 and smooth, or are ribbed and much higher than broad, and in these 

 respects diff'er, so far as I am aware, from very nearly all higher 

 butterflies.'!' The egg of Parnassius however, is an extraordinary 

 exception, resembling that of the Lycsenids described below. The 

 caterpillars are never spined, but either approximately naked, pilose, 

 or provided with fleshy tubercles or filaments. The chrysalids are 

 hung by a loose girt, and are the only girt chrysalids which have the 

 head armed in front with a single centra) prolongation or a pair of 

 prominent tubercles. 



One characteristic mark of the gossamer-winged butterflies is their 



*See Dodge in The Rural Carolinian III, 594, (1872). 



fThe egg of Danaida Flexij^pus and, approximately, those of Brcuthis, come 

 near the latter class. 



