PAPILIOKIDAE : RHODOCEllIDI. 1841 



and sharply clefliied in the male, generally inilistiiict, subobsolete or powdered in the 

 female; in both it is narrow and is very irregnlar in its distribntion, according to in- 

 dividuals, but in the males it is twice as broad in the lower subcostal as in the upper 

 subcostal interspace ; the upper third of the wing, limited by the lowest subcostal 

 uervule, is tinged with orange yellow in the male, while in the female the whole wing 

 is more or less tinged faintly with greenish yellow. 



Beneath : Fore wings pallid, more or less tinged with yellow on the basal tliird, par- 

 ticularly in the female, and flecked with ferruginous at the apex especially next the 

 margins ; a minute, black or dark brown spot at the upper extremity of the cell. 

 Hind winrjs pale yellow, more or less heavily but generally very lightly and delicately 

 flecked witli ferruginous in scattered dots or short transverse threads, which show a 

 tendency to cluster into minute, regularly distributed spots along the basal half of the 

 costal margin and in a straight, transverse streak which runs from close to the tip of 

 the middle subcostal nervule to just within the extremity of the internal uervure, 

 broken in the median interspaces ; along the outer edge of this line the ferruginous 

 dots and threads appear to cluster and to become more and more scattered as they 

 outwardly depart from it ; in addition to which there is usually a small ferruginous 

 spot in the middle of the median interspaces ; occasionally the whole wing is decidedly 

 tinged with brownish ferruginous by the multiplicity of these markings, but the rela- 

 tive distribution still remains the same; there is also at the upper outer extremity of 

 the cell a minute black spot. Expanse of wings, J , 38-44 mm. ; ? , 42-46 mm. 



As becomes its name, Mexico is the proper home of this species, but it 

 inhabits also a considerable territory in the southwestern United States, 

 being found throughout most of Texas, Arizona and southern California, 

 and east of it even extending occasionally northward not only into Kansas 

 and Nebraska, but even into Iowa, Illinois and Wisconsin, and it has once 

 been found in an extreme southwestern point in Ontario, — Point Pelee 

 (Saunders). 



Nothing whatever is known of its early history and no one has made 

 any record of its seasons. 



NATHALIS BOISDUVAL. 



Nathalis Boisd., .Spec. gin. LiSp., i: 589 (1836). 



Imago. Head moderately broad, especially above ; front half as bro.ad again as 

 high, a little broader above than below, scarcely at all tumid, very uniform ; vertex very 

 broad posteriorly, somewhat tumid with a sharp and rather deep, transverse snlcation 

 just behind the antennae. Eyes small, not full, naked. Antennae considerably shorter 

 than the abdomen, widely separated, composed of about thirty-three joints, of which 

 twelve or thirteen form the ovate flattened club which is a little more than twice as 

 long as broad, is very broadly rounded apically, increases regularly on the basal half, 

 and whose broadest joints are four times as broad as long or as the stalk, the 

 longest joints of the stalk about three times as long as broad. Palpi long and very 

 slender, the Ijasal and middle joints of about equal length, the apical joint very short. 



Fore wings long, nearly twice as long as broad, regular, the apex well rounded ; costal 

 margin gently .arcuate to near the tip, one-fourth louger than the inner margin, the 

 outer margin gently convex. Costal nervure longer than the cell ; subcostal nervure 

 with three equidistant and distant, superior, simple Ijr.anches, the middle arising from 

 the apex of the cell, which is about half as long as the wing. Hind wings elongate, 

 well rounded, long in the subcostal region, half as long .again as broad. No precostal 

 vein ; vein closing the cell striking the last subcostal and median nervules at equal 

 distances from their base. 



