80 ARCTIAD.T^. 



Subfamily LITHOSIAN^. 



Proboscis usually well developed, but often aborted ; palpi 

 usually short uud porrect, son)etimes reaching well beyond the 

 frons, often upturned, rarely reaching above vertex of head; antennaj 

 of male usually with bristles aud cilia, often bipectinate, sometimes 

 dilated or with tuft of scales on vipperside of shaft ; ocelli absent ; 

 tibiie with the spurs usually moderate, sometimes long or absent. 

 lore wing typically long and narrow, but in a large section short and 

 broad, the narrow-winy;ed genera having vein 5, and often vein 4, 

 absent. Hind wing with vein 8 coincident with the cell from base 

 to one-third or to near end of cell. 



The luore generalized forms of LhhosinncB have a very slightly 

 modified venatidu in the fore wing; in DidiKja all the veins arising 

 from the cell except 7, 8 ; and the subfamily probably has its 

 origin in an early Arciid form which was related to Acoatia and its 

 allies in the yocliti(hr. 



The normal evolution of the venation seems to have been that 7, 

 8 and 9, 10 should become stalked, that 9 should then anastomose 

 with 8 to form an areole, which in most of the genera has dis- 

 appeared by reduction, leaving vein 9 stalked with 7, 8 ; in the 

 genus Ilema especially the areole being often either present or 

 absent in different specimens of the same species. 



The genus Jjanasa presents in the male a most extraordinary 

 modification of the hind wing, which is probably unique in the 

 Lepidojjtera, the whole wing being reduced to a minute lobe below 

 the base of the fore wing, except the inner area, wliich is largely 

 developed, appearing at first siglit like a normal hind wing, but in 

 reality rotated at base, the upperside becoming the functional 

 un'lerside and the inner margin the functional costa. 



The Lithosiame as a group present great variety of s ructure as 







1 



Fig. 25.— Larva of Philagria entella. \. (From Moths Ind. vol. ii.) 



regards both venation and secondary sexual characters, so that the 

 genera and sections of genera are very numerous. 



Some of the most generalized forms seem to be Hemonia, Tro- 

 jifinne, and the genera allied to Nudana ; whilst another gene- 

 lalized form Castalo, with veins 7, 8 and 9, 10 stalked, seems 



