Allotinus drumila, the crenulate darkie,[1] is a small butterfly found in India (Assam, Sikkim), Burma, Thailand, Laos, Vietnam, and Yunnan (China) that belongs to the lycaenids or blues family.

Hindwing: costal margin above the subcostal vein and in a line with it up to the termen similarly very dark blackish-brown, the rest of the brown colour uniform without any white.

Hindwing: dull pale brown thickly mottled with catenulated spots and strigeo of dark rusty brown; catenulated, somewhat broken, transverse irregular bands of the latter colour cross the base, middle and apex of the cell; a similar short band is placed at right angles to the dorsal margin and curving slightly upwards terminates at vein 3.

Forewing: apical, terminal and tornal areas black, the inner margin of the black commences just before the middle of the costa, and runs obliquely outward in a sinuous curve to base of the apical fourth of vein 2, thence it is produced for a short distance inwardly along that vein and terminates at the middle of the dorsal margin.

Hindwing: with minute brown speckles, more or less lightly and irregularly stained with rusty brown; basal half with obscure, transverse, narrow, macular, earthy-brown bauds that are well-defined only anteriorly, the basal one produced up to the dorsum; a short dark-edged transverse band from the tornus to vein 4 running parallel to the costal margin, the lower edge of the band acutely and irregularly dentate; the terminal and tornal areas below this band washed with earthy brown.