196 



postcr'or extremity of the alimentary canal is protected lieneatli T)y 

 a corneous sheath, which extends beyond the centrum or body of 

 the upper pair of abdominal appendages, sometimes nearly to the 

 extremity of the appendages, carrying the vent beyond the centrum ; 

 while in the Astyci, the extremity of the canal is not protected by 

 any extruded sheath, but opens at the very base of the inferior 

 Avail of the centrum. 



In the Hesperides, the prevailing color of the butterflies is dark 

 brown, marked with white or translucent angular spots; the an- 

 tennae generally have a long club roundly bent or with a sinuous 

 lateral curve ; in the Astyci the prevailing tints of the wings are 

 tawny and black, marked also, but often feebly, with pale, some- 

 times vitreous spots ; the antennae are provided with a stout club, 

 which generally tapers rapidly and terminates in a slender pro- 

 longation, recurved at about a right angle; but in a few genera the 

 crook is very slight, or wholly wanting. 



The body of the Hesperides is proportionally stouter than in the 

 Astyci, and their flight is generally swifter and more direct, although 

 in some genera the movement is unusually slow, in the higher Hes- 

 perides, when the insect is at rest, all the wings are held equally 

 erect; in the lower groups, the Avings are either perfectly or almost 

 perfectly expanded, or else they present the inequality of position 

 characteristic of the Astyci, where the hind wings are usually hori- 

 zontal or partially raised, while the fore wings are A'ertical, or at 

 least more elevated than the others. 



The earlier stages seem to present no peculiar distinctions, if we 

 except the eggs; in the Hesperides these are always distinctly rib- 

 bed vertically, and are almost always taller than broad ; while in 

 the Astyci the eggs are smooth and pretty regularly hemispherical, 

 usually broader than high. The caterpillars of Hesperides gener- 

 ally feed upon leguminous plants, and live in horizontal nests made 

 of leaA^es; the Astyci feed on Gramineae, and generally construct 

 vertical nests among the blades. 



To the former group — Hesperides — belong such genera as Pyr- 

 rhopyga, Erycides, Thymele, Thorybes, Achylodes, Erynnis and 

 Hesperia. To the latter — Astyci — Ancyloxypha, Thymelicus, Cy- 

 clopides, Atrytone, Pamphila, Augiades, Limochores, Prenes, Cal- 

 podes and Lerema. 



