GKOUPS AND FAMILIES 71 



21. STILBID^E. Imago with the thorax smooth ; the 

 abdomen long, smooth, slender in the male ; the an- 

 terior wings narrow, in repose partly overlapping and 

 forming a very inclined roof. Larva smooth, cylin- 

 drical, thick ; with 16 legs ; feeding on grasses during 

 the winter. 



We have only 1 species, Stilbia anomala. 



22. CATEPHIM:. Imago with the antennae filiform 

 and sometimes pubescent in the male ; the thorax much 

 crested ; the abdomen more or less crested ; the wings 

 thick, rather dentate ; the posterior wings often whitish 

 or transparent. Larva elongate, with 16 legs ; feeding 

 exposed on trees. 



We have only 1 British species, Catephia alcliymixta, 

 of which a single specimen only has occurred ; it was 

 taken by Dr. Wallace, in the Isle of Wight, in Sep- 

 tember, 1858. 



23. CATOCALID^E. Imago of large size with the an- 

 tennge long, slender, pubescent in the male ; the thorax 

 slightly crested ; the abdomen long, conical, slightly 

 crested ; the wings broad, thick, in repose forming a 

 very flat roof; the posterior wings gaily coloured. 

 Larva elongate, flattened beneath, and attenuated at each 

 end, with fleshy filaments on the sides above the legs ; 

 feeding on trees, and resting attached to the trunks. 



This family includes the Ked Underwing, the Crimson 

 Underwings, and the Clifden Nonpareil. We have only 

 4 British species. 



24. OPHIUSID.E. Imago of medium or large size, 

 with the thorax robust ; the abdomen smooth, more or 

 less conical in the male ; the wings thick, the anterior 

 wings with the lines well marked. Larva smooth, elongate, 

 with the anal legs and posterior ventral legs very long. 



