158 ENTOMOLOGY. 



a sub-costal cell, and a strong vein dividing the discal cell longi- 

 tudinally into two cells; larva? boring in solid wood. Prionoxystus 

 robinice Peek, is the oak and locust tree-borer. 



Family Thyrididse. — Small, richly colored moths with simple an- 

 tenna?, the wings small, the hinder ones more or less angular; the 

 discal cell of the fore wings open. Thyris maculata Harris, T. 

 lugubris Boisd. 



Family Sesiidae, — Small moths with brilliant colors, long, narrow, 

 more or less transparent fore and hind wings, and thickened an- 

 tenna?; larva? boring in the stems of shrubs and trunks of trees. 

 Sesiapyri (Harris); Melittia ceto Westw., the squash-vine borer. 



Family Sphingidae. — The hawk-moths are large insects with thick 

 bodies, spindle-shaped antenna?, thick palpi; usually a very long 

 tongue; the fore wings are rather narrow, the apex sharp, and they 

 have a small, short discal cell. Caterpillars with a smooth or granu- 

 lated skin, and a hump or horn on the eighth abdominal segment; 

 usually pupating in the earth, the pupa often with the tongue-case 

 large and free. In Hemaris the body is bright-colored, and tie wings 

 transparent in the middle (//. thysbe Fabr.). The larva of Thyrem 

 abbotii has a disk-like hump instead of a horn. In Smerinthus the 

 tongue is short and weak; S. excceeatim Ab. and Sm. In Cha?ro- 

 campa and its allies (Chcerocampince) the thorax is not tufted, and the 

 outer edge of the wings is more or less hollowed out; in the 

 Sphingiiur the thorax is tufted; the tongue long and the outer edge 

 of the wings convex; SpJiinx celeus Hiibner is the potato or tomalo 

 worm, and S. Carolina Linn., the tobacco worm of the Southern 

 States. The larva? of Ellema have no horn; EUe?na7iarrisiiC\emcns. 



The butterflies appear to form a super-family, the Rhopa- 

 locera, and are divided into four families. They differ 

 from moths in their club-shaped antennae; in the wings 

 being elevated when at rest, and their peculiar venation; 

 the lack of a bristle connecting the two wings; and from 

 their day-flying habits are called diurnal Lepidoptera, The 

 larvse vary greatly in form and ornamentation, but with 

 rare exceptions (a very few Hesperians) they are not borers, 

 and none of them spin a perfect cocoon, the chrysalis 

 either being fixed by the tail head-upwards and held in 

 place by a silken thread passing around the body, or it 

 hangs suspended by the tail; others (Rurales) generally 

 fasten themselves longitudinally upon the leaf or stem of a 

 plant, while the Hesperidae lie inside of a rolled leaf, with 

 silken threads around the body. * 



* The definitions of the five families of butterflies are in part 

 copied from H. W. Bates's "Lepidoptera of the Amazon Valley" 

 (Trans. Linn. Soc, London, 1862). 



