320 THE GEOMETRINA. 



ing the last pair of these members in the caterpillars 

 which are provided with a greater number of legs. 

 This peculiar arrangement of the prolegs induces a 

 corresponding peculiarity in the progression of the 

 creature, which, instead of crawling along with a 

 smooth gliding motion, advances by a series of steps, 

 the fore part of the body being first stretched out to 

 its full extent, and the anterior or thoracic legs at- 

 tached, when the hinder portion, bearing the prolegs, is 

 drawn close up to it, so that the intermediate segments 

 form a loop. The prolegs then attach themselves 

 to the object on which the caterpillar is walking, the 

 fore part of the body is again extended, the abdomen 

 brought up again, and so on, the process being re- 

 peated as long as the caterpillar is in motion. The 

 pupa, which is attached to sheltered spots in the walls 

 or palings, or to the lower surface of the branches of 

 the bushes, is of a dark brown or blackish colour, 

 with bright yellow rings upon the abdomen. 



In most essential particulars both of structure and 

 habits, a very large group of Moths agree closely with 

 this common insect. They all have the slender body 

 and ample wings, which give them a more butterfly- 

 like appearance than any of the preceding Moths, 

 and this is heightened by the gay colours which they 

 often present, although very few of them are diurnal 

 in their habits, the majority only coming abroad in 

 the later twilight. The antennae are long and bristle- 

 like, and often fringed or plumose, especially in the 

 males ; and the hinder legs are distinctly longer than 

 the intermediate pair. The caterpillars in all cases 

 exhibit the same arrangement of the feet as that of 

 the Magpie Moth, that is to say, they possess the 

 usual six thoracic legs, one pair of abdominal prolegs, 



