CERUEA VINULA. 147 



back and the lower part of the body ; the dorsal mark 

 begins wide on the front of 2, narrows thence with a 

 straight slope to the hump on 4, then widens with a 

 straight slope through 5 and 6, and on 7,8, and 9 

 varies a great deal, being at its widest on 8 ; through 

 9 and 10 it slopes up again, on 11 has nearly parallel 

 sides, widens through 12 to the front of 13, and then 

 narrows back to the flap. This summer I reckoned 

 six good variations in the flaps and stirrups of the 

 dorsal saddle ; the simplest form had the saddle swel- 

 ling out with a gentle curve on 8, but did not come so 

 low as the spiracle by more than 1 mm. The next 

 form to this had the saddle on 8 extended in a sort of 

 obtuse angle to just the level of the spiracle, but no 

 further ; then there was a form in which the flap came 

 just below the spiracle, and below it, quite on the leg, 

 a somewhat rounded spot or stirrup, but without any 

 connecting link. Then there was the form in which 

 the saddle-flap came as low as the spiracle, and con- 

 tinued down the side, quite narrow at the spiracle, 

 but swelling out into an irregular blotch or stirrup on 

 the leg. Then there was the form with this flap and 

 stirrup on 8, and on 9, below the spiracle, a large three- 

 lobed spot ; and, lastly, the form showing the greatest 

 development of the saddle which I saw, with the flap 

 on 8 covering all the side of that segment except just 

 a small spot by the spiracle, and reaching down into 

 the leg, and on 9 a similar but narrower flap reaching 

 nearly as low ; in no case did I see the spiracle, either 

 on 8 or 9, enclosed in any extension of the saddle-flap. 

 This dorsal mark varies in depth of colour, always 

 growing paler as the larva matures. It has a greenish 

 tint on the front of 2, and after that, it is brown, more 

 or less tinted with purple or lilac, and more or less 

 freckled in long streaks of greenish-white. (Dr. Chap- 

 man tells me that on the Continent this summer he 

 saw larvse paler in this way with white brindling than 

 he had ever noticed at home.) The border of the saddle 

 is darker in tint, and so are the flaps and spots on the 



