NORTH AMERICAN LEPIDOPTERA. 157 



The most common of the American forms, and at the same time 

 the most variable. It varies from an almost immaculate gray to a 

 form with a distinct fuscous shade and an obvious, longitudinal, 

 blackish line or shade. None of the transverse markings are dis- 

 tinct, yet there is no difficulty in recognizing the species, because we 

 have no other at all resembling it in our fauna. 



The species was first figured in all its stages by Madame Merian 

 in her " Insects of Surinam," and until recently this was the only 

 knowledge of the early stages. 



The genitalia have the general form of the genus ; the hooks are 

 rather long, moderately close together and but little divergent at tip ; 

 the inferior plate is very similar in form. The side pieces are elon- 

 gate, narrowing to a somewhat abrupt tip ; clasper stout, corneous, 

 somewhat twisted, with a rather spatulate, pointed tip. 



Rev. W. J. Holland has given a very good description of the 

 larval forms. 



D. obseura Fabr., Syst. Ent. 538. Sphinx; Sp. Ins. ii, 142, Sphinx; Mant., Ins. 

 ii, 94, .'^;;/jf)(X- ; Eut. Syst. iii, 1, 361. Sphinx; Gniel., ed. Linn. S. N. 2375, 

 Sjjhinx ; VVlk., C. B. M. Lep. Het. viii, 226, ^nceri/j: ; Clem., Journ. Ac. N. 

 Sci. Phil, iv, 176, Anceryx : Morr., Syn. 1862, 201, Anceryx ; Grt.. Proc. Ent. 

 Soc. Phil. V, 78, Erinnyis; G. & E., Pr. Ent. Soc. Phil, v, 168, Erinnyis ; Grt, 

 Buff. Bull, i, 27, Dilophonota ; Bd., Sp. Gen. Lep. Het. i, 132, Anceryx ; Butl., 

 Tr. Zool. Soc. Lond. ix, 604, Dilophonota ; Guudlach, Cont. Ent. Cuba, 220, 

 Dilophonota. 



stheno Hiib., Saml. Ex. Schmett. ii. Erinnyis: Wlk., C. B. M. Lep. Het. viii, 

 226, pr. syn. ; Bd., Sp. Gen. Lep. Het. i, 132, pr. syn. 



rhcBbus Bd., Lep. Guat. 1870, 72, A^iceryx ; Butl., Tr. Zool. Soc. Loud, ix, 604^ 

 pr. syn. 



Head and thorax dark gray ; head with a distinct tuft between the antennae ; 

 sides paler; front with two indistinct lines; thorax anteriorly dusky, or with 

 indefinite lines, sides also with a dusky line. Abdomen dusky gray, not banded, 

 but with two brownish dorsal lines. Primaries ashy gray, powdery, with the 

 sliadiugs and markings almost identically like those of D. ello, and they will not, 

 therefore, be described in detail. Secondaries dull red, with an obscure brown 

 marginal baud, sometimes merely a dusky powdering; a grayish anal patch. 

 Beneath reddish, outwardly shaded with fuscous, with an extra discal series of 

 dots. Expands 2 — 2.25 inches ; 50 — 56 mm. 



Hah. — Pa. (?), Texas, Mexico, West Indies, South America. 



Easily recognized by the small size, gray primaries and unhanded 

 abdomen. Specimens of this very rarely range Northward, and a 

 specimen in my possession was said to have been taken in Pennsyl- 

 vania. I do not know the source whence I obtained it and I cannot 



