( v:,:\ ) 



other segments togetlier ; comb of midtarsus iiulicateil by a few long bristles : 

 paronjxhium with or without long hibe (seasonal difference?). Mesouotum and 

 occipnt grey or black, with intergradations, up])er half of mesothoracic tegnla also 

 grey or black, with a rather indistinct blackish middle line. Forewing : a black 

 line upon R', entering cell ; the white band at the distal side of the weak black 

 snbmarginal Hue much broader than in c/eerst's. 



(?. Tenth abdominal tergite gradually narrower to end, which is abruptly 

 pointed, gradually curved, subcyliudrical, being coavex above and somewhat less 

 so below ; steroite short, broad, not sinuate mesially, the sides turned upwards 

 (PI. XXVIII. f. 12, side-view; f. 13, dorsal view). Clasper as in chersis ; harpe 

 (PI. XXXVIII. f. 6) very different from that of all the other Ilyloicus, consisting 

 of a long, flat, tapering plate whicli terminates iu a point ; its dorsal edge is 

 continuous with the subdorsal fold of the clasper, which fold bears very long 

 bristles ; its ventral edge is more or less irregidarly sinuate and bears here and 

 there a small sharp tooth. Penis-sheath (PI. XXIX. f 5) not unlike that of 

 cuncouverensis, but the process longer, its apex slightly incrassate, rounded, almost 

 knob-like. 



¥. Vaginal plate (PI. XX. f. IS) with a very large cavity, into which opens 

 the vagina, the cavity extending to near tlie base of the plate ; its roof is more or 

 less contracted in dry specimens, especially proximally, so that the opening is 

 not of the same size or of the same shape in different individuals ; the figure is 

 taken from a specimen in which the edges of the roof of the cavity approach each 

 other, the plate bearing in this case an obvious resemblance to that of lanceolatu ; 

 the jilate differs from that of chersis not only in the much larger size of the cavity, 

 and the much more proximal jjositiou of the mouth of the vagina, but also in the 

 presence of a broad, ovate or elongate, mesial tubercle, homologous to the longer 

 and narrower mesial rounded keel of Iniieeolafa. 



Larva and chrysalis not described. 



We unite here under perelegans two forms, one with grey, the other with black 

 mesonotnm, the forms corresponding to those of //. vancouverensis, but differing 

 from one another not only in the colour of the thorax and wings, but also in the 

 structure of the claw-segment of the tarsi. The form with grey thorax is generally 

 considered identical with cliersis chersis, or chersis oreodaphne, from which it is, 

 however, specifically distinct. Both forms of jjcrelegans agree in the sexual 

 armature and in some essential characters of the wings, and from this we conclude 

 that the peculiar divergency in the development of the claw-segments does not 

 indicate specific distinctness of the two, though we were very much surprised 

 when we discovered that we had here a case of apparently quite constant struitural 

 dimorphism. The differences may be seasonal, but the dates of our specimens, as 

 in the case of rancot/rcrcnsis, do not absolutely point to this ; breeding alone will 

 clear up the question. 



a'. H. prrelcgnns f. asrlhts nov. (I'l. Xlll. f. 'Z, cS)- 



In collections confounded with //. chersis oreodaphne. — Type : Colorado. 



c? ? . Occii)ut and mesonotnm grey ; ground colour of forewing also almost 

 uniformly grey, white snbmarginal band bi'oad ; fringe with distinct white spots. 

 Parouj-chium reduced (PI. LXIV. f. 14. 1.")), irifliout lolie. 



