THE DELTA-MOTHS. 475 



like that of the Greek letter A. For the same reason I 

 have called them Delta-moths. The body, in these moths, 

 is long and slender. The fore wings are long and rather 

 narrow, and cover the hind wings nearly horizontally when 

 at rest. The feelers are generally very long, flattened side- 

 wise, and more or less turned up at the end. The tongue 

 in some is of moderate length, in others it is very small 

 or invisible. The antenna are long and generally simple 

 or bristle-formed in both sexes ; in some males, however, 

 they are feathered, and in a few others they have a singular 

 knot or crook in the middle. The legs are long and slen- 

 der; and the first pair is often fringed with tufts of long 

 hairs. Most of these moths fly at night ; a few are on the 

 wing in the daytime also. They generally prefer moist and 

 shady places, where the long grass and thick foliage shelter 

 them from the light and heat of the sun. Some of them 

 frequent houses. 



The meal-moth (PyroHis farinalis), (Plate VII. Fig. 8,) 

 the caterpillar of which may be found in old flour-barrels, 

 is often seen on the ceilings of rooms, sitting with its tail 

 curved over its back. The fore wings of this pretty moth 

 are light brown, crossed by two curved white lines, and 

 with a dark chocolate-brown spot on the base and tip of 

 each. The tabby, or grease-moth (Aglossa pinguinalis), 

 the larva of which lives in greasy animal substances, is also 

 to be found in houses, and is known by its narrow glossy 

 wings, of a smoky gray color, crossed by wavy lighter- 

 colored bands ; its tongue is not visible. The motions of 

 some of the day-flying kinds (iSimaethis) are very curious. 

 When they alight upon a leaf, they whirl round sidewise, 

 in a circular direction, with the head in the centre of the 

 circle, and then return in the contrary direction, and repeat 

 these gyrations several times in succession. 



The larvae or caterpillars of the Delta-moths are long 

 and slender, tapering at each end, and naked, or with only 

 a few short hairs, which are rarely visible to the naked eye. 



