NORTH AMERICAN LEPIDOPTERA. 121 



zonata Dm., i, p. 57, pi. 26, fig. 5, Sphinx ; VVestw., ed. i, 52, pi. 26, fig. 1, 3Inc- 

 roglossa; Wlk., C. B. M. Lep. Het. viii. 88, pr. syn. 



ixion Linn., S. N. ii, 803, Sphinx ; Fabr., Sp. Ins. ii, 154, Sesia ; Mant.. Ins. ii, 

 98; Ent. Syst. iii, 1, 379, pr. syn. ; Gmel., ed. Linn. S. N. 2386, Sphinx; Wlk., 

 C. B. M. viii, 88, pr. syn. ; But!., Tr. Zool. Soc. Lond. ix, 530, pr. syn. 



According to Grote much smaller than the preceding, which it 

 resembles. On the primaries the median white band is obsolete, and 

 the subterminal arcuated baud of whitish semi-transparent spots is 

 reduced to two or three unequal, irregular spots toward the middle 

 of the wing. Beneath, the median band is entirely wanting, while 

 the subterminal spots are as on u})per surfaces. The yellow scales 

 on u])per surface of the posterior wings in A. titan are absent, while 

 the costa shows a paler, somewhat whitish shade. The abdomen is 

 ])aler and the brown terminal segmentary bands are brighter and 

 more reddish than in A. titan. Expands 1.80 inches; 45 mm. 



Hub. — Florida, ranging northward occasionally to Massachusetts ; 

 Cuba, South America, Lower California. 



None of the characters pointed out by Mr. Grote are constant 

 AVithin a limited range this is an extremely variable species. The 

 discal spot may be al)sent, and from this point to a distinct transverse 

 bar closing cell I have seen all intergrades. The upright, geminate, 

 transverse line reaching to the cell may be very strongly marked, or 

 not recognizable at some portion of its course. The outer band of 

 lunulated spots may be geminate in part, in which case the lunules 

 are narrow, or the lunules may be broad and distinct, and in a single 

 series. The terminal space may or may not be paler. The abdomen 

 varies also ; the white band is constant in my experience. The 

 fourth segment is sometimes an intense deep black, the fifth with a 

 round black spot on each side of the middle, the sixth again entirely 

 black. The black may be replaced by brown or red in the ordinary 

 form, or the entire abdomen, except the third segment may be oliv- 

 aceous yellowish. I therefore re])eat that I am very sure that titan 

 and tantalus are identical, while fadus is probably distinct, but as 

 the settlement of this question is rather for the entomologists in the 

 true home of the insect I follow Mr. Butler in the synonymy. 



Ixion also seems to me much more likely to he. fadus than tantalus, 

 but in the interests of a stable nomenclature I retain the present 

 synonymy, since there can never be any positive certainty as to the 

 form Linnaeus really had before him. 



TRANS. AMEK. ENT. SOC. XV. (16) JUNE, 1888. 



