TORTRICINA. 285 



Genus IV. CHROSIS, GUENEE. 



Palpi longer than the head, ascending, remote. Basal joint pyri- 

 form, truncate ; apical as long as the basal, slender, terminating in 

 a point ; middle stout, slightly curved, thickest near the apex, more 

 than three times as long as the apical. Maxillae slender, as long as 

 the palpi. Thorax robust, ovate. Anterior wings : in length ex- 

 ceeding twice the width. Costa slightly arcuated ; apex obtuse ; 

 apical margin much, and the dorsal margin slightly, rounded. The 

 costal vein reaches to the middle of the margin ; the discoidal cell 

 capacious, lying towards the middle of the wing, extends two -thirds 

 its length ; the subcostal nervures equidistant. Posterior wings : 

 apex obtuse ; the apical margin concave. Abdomen longest in the 

 <5 , stout ; and with a small tuft at the apex in both sexes. 



This genus is established by M. Guenee for the reception of 

 the species herein assigned to it, and one or two others, which 

 we have now dissociated, the structural details warranting the 

 separation. As at present restricted, it is still an incongruous 

 group, but is nevertheless adopted until the habits and economy 

 of the larvae not only justify, but indicate, a more natural 

 position. 



The British species are thus arranged : 



A. Anterior wings with dull, silvery streaks, and alter- 

 nated light and dark markings between .... Species 1 



B. Anterior wings clouded with black, the tips ochreous, 



and with lustrous blue streaks superposed .... Species 2 



1. tesserana, Schiff. Alis anticis albidis, flavis vel aurantiacis ; 

 maculis quinque tessulatim positis, cinereis, fuscis, ferrugineis aut 

 castaneis ; strigis argenteis flexuosis ; posticis cinereis. tf Exp. 

 al. 4-6 lin. 



Head and face bright ochreous. Eyes black. Palpi longer than 

 the head ; ochreous above, between, and beneath ; dusky at the sides 

 and apex. Antennas brown. Thorax and patagia dull ochreous, 

 irrorated with iron-grey. Anterior wings glossy, with alternated 

 ochreous and ferruginous patches, and transverse lustrous blue 

 streaks between ; these streaks are thus disposed : one situated one- 

 fifth from the base, convex ; about the middle of the costa originate 

 two others, angulated ; and a fourth, nearly straight, reaching the 

 anal angle ; along the apex are a few, more or less distinct, similar 

 lustrous streaks. The spaces between the main streaks are alter- 

 nated above and below with ochreous and ferruginous ; the apical 

 space, however, is usually more suffused, and is ferruginous above 

 and below, and ochreous between. Apical scales ferruginous. Cilia 

 buff-colour, becoming iron-grey at the anal angle. Posterior wings 



