desired. Worthinj^ton's description aij;rees in every particular with 

 Hijbner's, and a specimen of Oberon, kindly given me by Mr. H. Ed- 

 wards, is an exact counterpart of Hiibner's figure, both above and 

 below, so that there can be no doubt that they are identical. 



Having settled the fact that Zestos is entitled to be catalogued among 

 our North American Rhopalocera, and that it is undoubtedly the same 

 as Oberon, the question of its specific worth at once presents itself. 

 Mr. Worthington has pointed out its striking resemblance to Eiidavms 

 Tityrus, Fabr. , but has mentioned the following differences as entitling 

 it to recognition as a good species: " the yellow spots are less confluent 

 and more opaque, the general color deeper and fringes not divided by 

 brown on the veins; beneath, it differs conspicuously in the more uni- 

 form color, the purplish cast and entire absence of the large silver spot 

 so prominent in its ally. ' ' Before attempting to show that these char- 

 acters are not of specific value, but on the contrary belong to a rather 

 inconstant varietal form, I would state that my conclusions have been 

 reached with over i6o specimens of Tityrus and Zestos before me. 

 When compared with specimens of Tityrus from the northern portion 

 of the United States and from Canada the yellow spots of Zestos are 

 "less confluent and more opaque;" but when compared with speci- 

 mens from Arizona, Yucatan, F'lorida, or even North Carolina and 

 Tennessee, it at once becomes evident that these differences no longer 

 exist. I have before me eight specimens of Tityrus collected in Arizona 

 by Mr. H. K. Morrison in 1882 and 1883. All of these without a sin- 

 gle exception have the yellow spots considerably less confluent than in 

 Zestos, and three of them, together with specimens from Tennessee, 

 Florida and Yucatan, have the spots somewhat more opaque, the two 

 larger ones being a deep orange in place of honey-yellow, as is usually 

 the case in Tityrus. 



Compared with bred and fresh specimens of Tityrus the "general 

 color" of Zestos is undoubtedly "deeper," but as starving the larvae 

 will frequently produce this condition, and sudden changes in the tem- 

 perature always do so, it cannot be used even as a character for varietal 

 differences, much less for specific. Unfortunately many of my speci- 

 mens of Zestos are far from being bright and perfect ones, and there- 

 fore I cannot so readily compare the fringes, which certainly seem to 

 be, with one or two exceptions, unicolorous, and not alternately brown 

 and ashy as is usual in Tityrus. However, I find among my Arizona 

 and Tennessee specimens of Tityrus three that closely approach Zestos 

 in this respect ; and among my specimens of Zestos one that is nearly 

 as bicolorous as typical Tityrus, and fully as much so as those from 

 Arizona. 



From these comparisons it will be seen that the upper side affords no 

 constant differences, and that consequently it is beneath, that we must 

 look for those characters which should be considered specific. In 



