16 Mr Lister, Notes on the genus Liparis. 



Notes on the genus Liparis. By J. J. Lister, M.A., St John's 

 College. 



[Read 27 October 1902.] 



The degeneration of the alimentary system in two at least of 

 the British representatives of this family of Moths, Porihesia 

 auriflua and Psilura monarcha, was referred to, the maxillae being 

 vestigial in character, not accurately opposable to form a proboscis, 

 and shorter than the labial palps. 



Sexual dimorphism, though not attaining the high degree 

 found in other members of the family as in Hypogymna dispar, 

 and especially in Orgyia (the Vapourers), is yet well marked in 

 P. auriflua, secondary sexual characters being found in the " expan- 

 sion " of the wings, colour, and the larger size of antennae and eyes 

 in the male sex. A paired longitudinal groove on the sides of the 

 4th abdominal segment of the male is probably homologous with 

 the much longer groove found in the males of many Noctuae, 

 notably in Xylophasia polyodon, extending from the 2nd to the 

 4th abdominal segment and lodging a remarkable tuft of hairs, 

 which springs from the front end of the groove and is protrusible ; 

 — an organ which appears to have been generally overlooked by 

 entomologists. 



In illustration of the high perceptive powers of the male of 

 auriflua an instance was given in which three assembled in the 

 neighbourhood of a female of this species, which had been dead for 

 three days, within five minutes after the laying open of the store 

 box in which the insect was pinned. 



When fertilisation of the eggs has been accomplished, the 

 insects rapidly die. Attention was drawn to the difference between 

 the conspicuous satiny white colouring of the three species Por- 

 thesia chrysorrhoea, P. auriflua and Liparis salicis and the quiet 

 buffs, browns and blacks of the other members of the family, con- 

 forming closely with their environment ; and it was pointed out 

 that there is a considerable body of evidence showing that the 

 conspicuous species are noxious to other animals, both in the 

 larval and adult state, by reason of the urticating properties of the 

 hairs. 



