240 INSECTS INJURIOUS TO VEGETATION. 



which resemble the latter closely in the winged state ; and thus 

 the series, from Procris and other moth-like Sphinges to the true 

 Moths, will be uninterrupted. The latter, on the whole, seems 

 to be the most natural course, and it agrees with the arrangement 

 of Dr. Boisduval, which I shall follow, with some slight changes 

 only. 



Agreeably to this arrangement the first family of the Bombyces 

 will be the Lithosians (Lithosiad^), so named from two Greek 

 words*, meaning a stone, and to live ; for the caterpillars of many 

 of these insects hve in stony places, and devour the lichens grow- 

 ing on rocks. (Such also are the habits of Glaucopsis Fholus, 

 one of the Glaucopidians.) On this account they are not properly 

 subjects for notice in this essay ; but as some of the larger spe- 

 cies are grass-eaters, are conspicuous for their beauty, and natu- 

 rally conduct to another family, particularly obnoxious to the cul- 

 tivators of the soil, it may be interesting to point out their distin- 

 guishing traits, and the manner in which the transition to the next 

 family is effected. 



The Lithosians are slender-bodied moths, mostly of small size, 

 whose rather narrow upper or fore wings, when at rest, generally 

 lie flatly on the top of the back, crossing or overlapping each 

 other on their inner margins, and entirely covering the under- 

 wings, which are folded longitudinally, and, as it were, moulded 

 around the body ; more rarely the wings slope a little at the sides, 

 and cover the back like a low roof. The antennae are rather 

 long, and bristle-formed ; sometimes naked in both sexes, more 

 often shghtly feathered with a double row of short hairs beneath, 

 in the males. The tongue and one pair of feelers are very dis- 

 tinct and of moderate length. The back is smooth, neither woolly 

 nor crested, but thickly covered with short and close feather-like 

 scales. The wings of many of the Lithosians are prettily spotted, 

 and they frequently fly in the daytinje like the Glaucopidians. 

 Their caterpillars are sparingly clothed with hairs, growing in lit- 

 tle clusters from minute warts on the surface of the body. They 

 enclose themselves in thin oblong cocoons of silk interwoven with 



* This is the derivation given by M. Godart,. Hist. Nat. Lepidopt. de France. 

 Vol. v., p. 10. 



