AMERICAN LEPIDOPTERA. 69 



Acontia biplaga Guenee. 



1852, Gu., Spec. Gen., Noet., ii, 218, Acontia. 



1857, Wlk.. Cat. Brit. Mus., Het., xii, 785, Acontia. 



1868, G. and R., Trans. Am. Ent. Soc, ii, 79, var. aprica. 



1874, Grt., Bull. BuflF. Soc. Nat. Sci., ii, 36, var. aj>rica. 

 Head dark gray ; collar gray mottled ; thorax else white or creamy ; abdomen 

 white or a little yellowish. Primaries dark gray or blackish, basal space more or 

 less white mottled inferiorly, rarely almost all white, the t. a line then forming 

 an oblique gray shade line followed by white. Normally the t. a. line is broken, 

 white, often obsolete superiorly. A large, quadrate, costal white patch at about 

 the middle of the wing inclosing the small, round, black orbicular. A smaller, 

 also quadrate white patch at the inception of the reniform. T. p. line broken, 

 black below the costal white patch, very deeply incurved below the cell. S. t. 

 line incomplete, more or less white, preceded by irregular and sometimes promi- 

 nent black spots, rather regularly and strongly trisinuate. A broken black ter- 

 minal line. Fringes cut by a white patch at about the middle, but this is a 

 variable feature and may be altogether absent. Reniform obscure, oval, partly 

 outlined in black, in rare instances black filled. Secondaries white, becoming 

 smoky outwardly, more broadly so in the female, with a smoky discal lunule. 

 Beneath mainly white or yellowish, primaries blackish toward apex, relieving 

 the subapical patch of upper side. Secondaries white, with a more or less obvious 

 smoky outer border, a blackish discal mark and a black spot at apical third of 

 costal margin. 



Expands 25-29 mm. = 1.00-1.15 inches. 



Hab. — Anglesea, New Jersey, September 4th (Smith) ; Hazleton, 

 Pennsylvania, August (Dietz) ; Decatur, Illinois, July lst-7th 

 (Barnes) ; St. Louis, Missouri, October 31st (Riley) ; Poncha 

 Springs, Colorado, July 14th (Oslar) ; Florida; Round Mountain 

 ( Hulst), Bastrop County (Meske), Texas. 



Twelve examples representing both sexes. The localities above 

 given are repre.sentative, and the insect occurs throughout the re- 

 gion east of the Rocky Mountains and south of New York, becom- 

 ing more abundant in the West and Southwest. 



The range of variation is not great and the species is, I doubt 

 not, perfectly distinct from aprica. In aprica a large part of the 

 median space is always white and the tendency is to darken the 

 basal space. In biplaga the median space is always dark, except 

 for the costal patches, and the tendency of variation is to lighten 

 the basal space. 



The primaries are moderate, trigonate, the apex a little marked, 

 but scarcely pointed. Secondaries with vein 5 weaker than the 

 others, on a short sj)ur from the end of the cell. Veins 3 and 4 

 branch about one-third from the end of the cell. 



TRANS. AM. ENT. SOC, XXVI I. SEPTEMBER, 1900. 



