GRAPTA V. 



This description applies well to the female Umbrosa, which alone of the sexes 

 of either form can be called glaucous, this word expressing the blue-grey color 

 with which the wings are sufiused. It is not often used by Fabricius. In his 

 Ent. Syst. I have been able to discover it but few tunes. One of these is used in 

 describing the American sjjecies, 3Icf/istanis Achcronta, the under side of which is 

 a shade of grey that nearly a])proaches the female Uinbrom. This latter is also 

 distinguished l)y a row of distinct black points crossing both wings. 



I conchide therefore that the female Umbrosa is the true Literrogationh, Fab. 

 This was the opinion of Godart. In Enc. Meth. IX, p. 302. he says; "Fabricius 

 has taken the male for C aureum of Linnaeus and has made of the female a sepa- 

 rate species under the name of Intcrroyatlonis.'" 



Eoisduval and Leconte give a figure copied from one of Abbot's drawings, com- 

 posed apparently of the upjser surface of Fabricii and the under surface of Umbrosa. 

 The shape is rather that of the latter. These authors state that although there 

 would seem to be more than one species, yet as the caterj)illars are the same, the 

 butterflies must be the same also. A correct conclusion from incorrect premises, 

 for it is not implied that caterpillars had been proved to be tlie same by breexling 

 from the egg, and resemblance in the larvae by no means indicates identity in 

 the imago. 



The figures of Iliibuer are admii-able, and re])resent butli sexes of Umbrosa, 

 under the name C aureum. I do iiot find Fabricii anywhere figured excejit in 

 the wood-cut of the female in Harris. 



The history of I/derrocfaiionis, and that of AJax, illustrates the defects of the 

 present system of determining genera and species, founded as it is on one stage only of 

 the insect's existence, and omitting the other three, the egg, larva and chrysalis, 

 from consideration. Certainly all these stages are important, if not ecpially'so, to 

 a true conception of either genus or species. Even so minute objects as the eggs of 

 butterflies, sometimes scarcely to be distinguished by the naked eye, and always re- 

 quiring examination under the microscope, are found to difier generically in shape 

 and ornamentation as decidedly as do the butterflies produced from them. jS[( (th- 

 ing can be more distinct than the smooth, spherical egg of Papilio, the granulated, 

 lenticular egg of Paruassius, the fusiform of Pieris, the ribbed ovoid of Vanessa, 

 the sculptured conoid of Argyunis, the dome-topped cylinder of Danais, or the 

 semi-sphere of Pamphila. And so far as I have been able to examine the eggs of 

 our butterflies, those of the same genus, besides bearing a generic resemblance, 

 have each their specific differences. Thus A./ax is distinguishable from Turnus, 

 or Troihts, or Philcaor; Phihdice from Eurytheme, or Alexandra. So with 

 Diana, Cijbcle, Aphrodite, and the Satyri and Hesperidce. 



The larvae and chysalids also fall naturally into groups, or in other words dif- 

 fer generically, though genera founded upon these groupings would disarnuige very 

 materially many of the highly artificial divisions at present recognised. And they 

 differ individually so that one need never be mistaken for another, even in such 

 cases of similarity as in the larvae of L. Disippus and X. Ursula. 



But, inasmuch as the imago is the only one of the four stages that is usually 

 known, the determining characters are sought in it alone, in the distribution of the 

 nervures, in peculiarities of legs, palpi and antennae, form of wings and markings 



