PHYCIODES I., II. 



eral sub-varieties, some of them in time to become distinct and well marked, 

 while the other two, Phaon and Vesta, remained constant. As the climate mod- 

 erated and the summer became longer, each species came to have a summer gen- 

 eration ; and in these the resemblance of blood-relationship is still manifest. As 

 the winter generations of each species had been much alike, so the summer gen- 

 erations sprung from them were much alike. 



And if we consider the metropolis of the species Tharos, or perhaps the parent 

 species back of that, at the time when it had but one annual generation, to have 

 been somewhere between latitudes 37^ and -40', on the Atlantic slope, and within 

 which limits all the varieties and sub-varieties of both winter and summer forms 

 of Tharos are now found in luxuriance, we can see how it is possible, as the gla- 

 cial cold receded, that only part of the varieties of the winter Ibrm might spread 

 to the northward, and but one of them at last reach the sub-boreal re^'ions, and 

 hold possession to this day as the sole representative of the species. And at a 

 very early period, the primary form, together with Phaon and Vesta, had made 

 its way southward, where all three are found now, neither of them, so far as 

 appears, having developed any marked varieties of the winter form. 



It is the female of the summer form of Tharos, and that variety of it which 

 discovers the brown discal jJatch on the under side of the hind Avings (Yar. B), 

 which Drury figured under this name, in 1770. Cramer's Tharos is stated to 

 have come from New York and reference is made in the text to Drury. But the 

 figures are coarsely drawn and rudely colored, and there has been some differ- 

 ence of opinion as to the real species intended to be represented by them. 

 Cocyta, Cramer, Figs. A, B, Plate 101, is Tharos male of the summer form 

 (Yar. A), and Fig. C is probably intended for female of same ; but the text re- 

 fers it to Surinam, and it is given with a doubt expressed as to whether it be- 

 longs to the male figured or not. Dr. Boisduval considers this Cocyta to be 

 synonymous with Morpheus, Fabricius, and locates it in southern California. 

 Fabricius describes Morpheus as a North American insect, and in language ap- 

 plicable to the summer form of Tharos. " Parvus. Alte omnes integerrimse, 

 fulvas, maculis margineque nigris. Posticos punctis sex nigris in strigam dispos- 

 itis versus marginem posticum. Subtus anticfe fulvse, nigro maculatie, pos- 

 ticas pallasceutes strigis undatis, margine punctisque sex fuscis." I therefore 

 call the species Tharos, the summer form Morpheus, the winter form 3farcia. 



The figures of the male Tharos in Bois. and Lee. are not very exact, but may 

 be taken to represent the form Morpheus. But the female must have been drawn 

 from Batesii, and evidently Dr. Boisduval had this insect before him when he 

 wrote these words : " We possess individuals which we consider as varieties, of 



