46 THE BUTTERFLIES OF NEW ENGLAND. 



riorly to a cur\ ing hook, which in its turn siniuhites the upper appendage 

 of the succeeding segment. The same is true of the Pa})iHoninae, as 

 Buchanan White has shown, only here it is deeply cleft niesially. A still 

 more singular anomaly occurs in Lilntheinae, which in the American 

 Hypatus resembles the Pierinae, while in the Eiu'opean Lil)ythea it takes 

 more the form of the Papilioninae. 



It is in the ninth segment, however, that the greatest variety of form 

 and structure is seen, the segment bearing hinged api)endages, serving with 

 the other external armature as cl<(.^j)htf/ organs, at the mating season. 

 This apparatus (33-37) may be simply descril)ed in general terms as con- 

 sisting of a median uncate upper organ moving vertically, and paired 

 laminate side pieces or clasjis moving laterally. The upper organ (the 

 sicula of Rambur, tegumen of Buchanan White, scaphium of Gosse) is in 

 general a pointed or forked hook, covering the apical organs above and 

 having an upward and downward movement. In its various developments 

 it may be said to consist of a main body or centrum with a})ical hook or 

 hooks, and curving or bent lateral arms ; these latter may be independ- 

 ently developed and conspicuous, as in Satyrinae and Lycaenidae ; or 

 soldered to the body or connate beneath the apical hook, and supporting a 

 common inferior armature of prickly points, as in Hesperidac ; or developed 

 as mere angular projections, as in Pierinae ; or, as in Papilioninae, where 

 the median process of the eighth segment (uncus of Gosse) nsnrps the 

 protecting function of the upper organ, they may form transverse prickly 

 and corrugated ribbons (the honiologue of the inferior armature of the 

 Hesperidac) lying near the base of the intromittent organ, which are 

 sometimes torn from their attachments in mating and left in the vestibule 

 of the female (61 :48) ; or finally they may be altogether absent, as in the 

 bulk of the Xymphalinae. The clasps (valvae of Rambur) admit of an 

 equal variety of development, but may in general terms be said to be usu- 

 ally composed of a base, with an up])er lobe and a blade hardly separable 

 from it, the former usually developing prickly or pointed upper processes 

 (styles of Rambur) and hind processes, the latter capable of bearing arma- 

 ture at any point at will, and generally furnished with many stiff bristles- 

 near the outer edge. In some of the Lycaeninae, especially the Theclidi, 

 the clasps may be very slightly developed and simple, forming a mere 

 channel for the support of the here enormously developed, apically flaring 

 intromittent organ ; or the upper lobe in other cases, as in the Papilioninae, 

 may form a large concealing flap (valve of Gosse), and the blade be devel- 

 oped as a curving prickly ridge (harpes of Gosse) lying within the valve. 

 The form and sculpture of these appendages varies in every species form- 

 ing excellent means for their distinction, and they thus become, says 

 Dufoiu", " the guarantee, the safeguard, of legitimate pairing." 



As connected with the outer tcijument rather than with the internal organs, 



