LEPIDOPTERA. 233 



grouped together, and form the costa or front edge of the wing ; 

 the median occupies the middle of the wing ; and the sub- 

 median and internal, the hinder, or internal, area of the wing. 

 The costal vein is usually simple, and joins the costa near its 

 outer third. The subcostal, near the middle of the wing, is 

 usually subdivided into five branches, which are called ven- 

 ules, while the median is usually subdivided into one venule 

 less, and the submedian and internal are simple. The last, or 

 fifth, subcostal venule, and the first median venule, generally 

 each throw out a small venule, which meet to form the discal 

 venule, thus enclosing a large central area called the discal area, 

 or cell. There are rarely any cross venules present. Some- 

 times, as in Hepialus, there is a transverse costal venule, and 

 an iuterno-submedian venule. They are usually found only in 

 degraded Lepidoptera, and recall the net-veined style of vena- 

 tion of the Neuroptera. 



The legs are slender, cylindrical, and weak. The coxae are 

 closely united with the thorax, the trochanters are spherical, 



FIGS. 155, 150, give a general view of the body of a butterfly denuded of scales. 

 FIG. 155. a, antenna ; 1, prothorax ; m, patagia, or shoulder-tippets ; k, mesoscutum ; 

 n, abdomen; A, costal edge of fore- whig; D, apex; C, outer edge excavated; E, 

 outer angle; B, inner edge; ab, discal cell; am, discal venules, throwing off the 

 independent vein, al. The dotted lines indicate the inner, middle and outer third 

 of the wing. FIG. 157 illustrates the mode of ornamentation of the wings 

 of moths; ab, am and al, the inner, the middle, and outer third of the wings. The 

 capitals are the same as in FIG. 155; sd, the basal line; sa, the inner line; s}>, 

 the outer, and ms, the marginal line variously waved, scalloped and angulated. 

 In most of the Noctuidas are the dentiform spot, 1 b; mo, the orbicular, and mr, the 

 reniform spots ; between the two latter often runs the transverse shade, um. In 

 FIG. 158, hind wing, /; indicates the "bristle" which fits into the "hook" on 

 the fore-wing, uniting the two wings during flight; cm, situated in the discal cell, 

 indicates the "lunule," and beyond are the outer and marginal dusky bands. 

 FIG. 159, 1 , internal vein; Ib, submedian vein; 2, 3, 4, 5, the four branches 

 (venules) of the median vein (in FIG. 100,5 becomes the independent venule); 

 6 to 12, branches of the subcostal (in FIG. 101, xii, is the costo-subcostal recurrent 

 venule). In FIG. 1G2, wings of the Hepialus, the venation is more irregular, and in 

 the fore-wing the discal cell is divided into an anterior and posterior discal 

 cellule, by the disco-longitudinal vein; sd, x, and s, accessory cells. In the Tineids 

 the venation is very simple. In FIG. 103, the submedian and internal veins have 

 disappeared; 9 is the costal vein; 2, 3, the two branches of the median vein; -i to 

 8, branches of the subcostal vein. In FIG. 1G4, the internal vein is shortened, and the 

 submedian forked, while the median and subcostal are merged together. From 

 Heinemann, in Morris's Synopsis, Smithsonian Miscellaneous Collections. Compare 

 also FIG. 29 on page 23. 



FIGS. 15(5 and 105. a, antenna, on one side wholly, and on the other partially, 

 pectinate; b, eye: /, ocellus; h, labial palpus; </, maxillae or "tongue;" o, coxa; 

 p, trochanter; q, femur; r, tibia; V, single anterior spur; r*, two middle tibial 

 spurs; 2, 3, two pairs of posterior tibial spurs; s, tarsus. 



