172 SPILOSOMA ACREA. 



colour, spotted with black ; on which account they 

 have been named Ermine and Leopard moths. 

 Like the tiger-moths, to which they are nearly re- 

 lated, they are subject to great variety in their 

 markings, even in the same species ; of the common 

 British species, S. menthastri, not fewer than eight 

 well marked varieties have been described. 



The wings of the male of S. acrea expand about 

 two inches, those of the female two inches three 

 quarters. Head, thorax, and upper wings of the 

 male cream-coloured, the surface of the latter with 

 numerous small black spots, five of which are placed 

 in a regular row along the anterior border, and six 

 on the external one ; hinder wings entirely yellow, 

 with a few black spots near the external edge and 

 middle. The abdomen is yellow, with a row of 

 black spots down the centre, and another on each 

 side ; the apex cream-coloured. 



In the female all the wings are white, with nu- 

 merous black spots, which are very variable in their 

 distribution, but there is a marginal row on the 

 hinder wings which doe3 not exist in the other sex. 

 The abdomen is coloured nearly as in the male ; eyes 

 and antennae in both sexes black. 



The caterpillar is said to be white when young, 

 and to become nearly black when full grown, a 

 transition to two extremes which is not common 

 even among a race of creatures subject to great 

 variation in regard to colour. In its intermediate 

 stages, the prevailing hue is reddish-brown. When 

 it has attained the period of its growth at which we 



