LYCAENINAK: TIIK GENUS THECLA. 871 



ami well arolioil in front, tho pi-oniinenco of tl\e hoiiil scarcely cansing any lack of 

 rcirnhirity in the curve, tlie basal wing tiil)ercle scarcely perceptible; the abdomen 

 quite reijnlar and eiiual in its curve, the posterior end beinj; pretty broadly rounded. 

 Viewed laterally tlie division between thora.x and abdomen is marked by only a small, 

 rounded hoUowinj;;; the thorax is most pvoniincnt just behind the middle of the meso- 

 thoras, and curves forward with a full and rather rapid, pretty regular, downward 

 arch, the same curve continued backward posteriorly with perfect regularity ; the 

 abdomen is roundly and regularly arched, highest, and slightly higher than the thorax, 

 at the tliird and foni'th segments, the posterior end of the body sloping about as 

 rapidly tliough generally a little less than the anterior, the apical half of the ninth ab- 

 dominal segment being perpendicular. Transversely the middle of the thorax is wcl\ 

 archetl, but considerably and rather broadly lioUowed in tlie middle of each of sides, 

 tlie summit well rounded; transversely the middle of the abdomen is very broadly and 

 regularly rounded, forming a scarcely depressed semicircle. Three-flfths of the 

 tongue exposed, the inner sides of the legs having the tongue interposed between 

 them. Basal wing prominences consisting of exceedingly slight, transverse, 

 oblique, low ridges. Posterior border of the wings straight. Whole body covered 

 with an interlacing, delicate network of raised lines, distinct under a lens, their points 

 of intersection generally raised a little and bearing a little wart; other independent 

 warts in the cells, broader than high, give rise to spiculiferous hairs, generally rather 

 short, sometimes very short. Ilooklcts short and very slender, the stem efiual, curved 

 somewhat at the tip, bearing a sudden lenticular expansion, which is bent downward 

 almost upon the stem, the lateral portions a little produced downward, the expansion 

 three times as broad as the stem. 



This group of tailed Theclidi occurs in the north temperate zone of 

 both hemispheres, in each of which it extends across the entire continent. 

 It is one of the most abundantly represented genera of our fauna ; no less 

 than five species occiu' within the limits of New England ; all of them 

 extend some distance to the west, most of them a considerable distance 

 to the south and nearly or quite all a short distance to the north ; only 

 one or two are at all common and one is exceedingly rare. 



The butterflies of this group are about the medium size for Theclidi and 

 of very elegant form ; their hind wings are furnished with two thread-like 

 tails of unequal length, their upper surface is uniform blackish brown, 

 occasionally ornamented at the base of the tails with a brilliant orange 

 spot ; beneath they are of various shades of gray or light brown with 

 double or triple, more or less complete, common, marginal rows of small, 

 pale spots or streaks, and on the hind wings a series of colored crescents, 

 which become quite large and conspicuous beside the anal angle. The 

 fore wings of the male are furnished with an obovate discal spot. 



The butterflies are all single brooded, and appear in the New England 

 region about the beginning of July and lay their eggs about the end of 

 the month. The eggs in some cases do not hatch until spring, or if they 

 do, the caterpillar probably hibernates without feeding, and the instct re- 

 mains in the chrysalis state — generally in June — from eight to seventeen 

 days. The caterpillars feed almost exclusively upon the leaves of trees 

 or large woody shrubs. 



The transformations of all but one of our species have been studied. 



