178 NOTODONTINA 



1. HYDRIOMENIDAE. 



Tongue developed. Forewings : 10 rising separate, anasto- 

 mosing with 11 and 9 (forming double areole), or rising out of 

 1 1 and anastomosing with 9 (forming simple areole). Hind wings : 

 5 fully developed, parallel to 4, 6 and 7 almost always stalked 

 or connate, 8 anastomosing with upper margin of cell from near 

 base to beyond middle, or sometimes approximated only and 

 connected by bar or shortly anastomosing beyond middle. 



A very large family, distributed in equal plenty throughout 

 all temperate regions, but becoming scarcer within the tropics. 

 The structure is very uniform throughout, and the generic 

 distinctions slight. Imago with body slender, forewings usually 

 broad. The type of markings of the forewings is here more or 

 less obscured by the development of a number of usually waved 

 transverse striae, alternately dark and light, which again tend 

 by coalescence to form six similar dark fasciae ; of these the 

 first often forms a basal patch, the second precedes the first 

 line (which is nearer the base than usual), the third and fourth 

 form the median band, limited by the median and second lines, 

 and the fifth and sixth border the pale subterminal line. The 

 markings of the hindwings are sometimes nearly as in the fore- 

 wings, but more often partially obsolete; those species which have 

 the hindwings distinctly marked always expose them in repose. 



Ovum broad -oval, rather flattened, with usually angular 

 reticulations. Larva elongate, slender, with few hairs, without 

 prolegs on 7-9 ; often imitating live or dead twigs and shoots. 

 Pupa usually subterranean. 



The relations of all the principal genera are indicated in the 

 diagram, in which is included (in brackets) the exotic genus 

 Notoreas, to furnish a common starting-point. 



PHYLOGENY OF HYDRIOMENIDAE. 

 Chloroclystis 



Trichopteryx Tephroclystis Operophtera 



I 



Lythria Xanthorhoe 

 I I 



[Notoreas] 



