142 THE ENTOMOLOGIST. 



orange-colour when deposited, but become almost black 

 before they are hatched, which event usually takes place 

 about the middle of July : the natural food of this Geometer 

 is not known : the larva itself appears to be unknown to the 

 lepidopterists of continental Europe : but young larvae, the 

 produce of eggs laid on a setting-board, feed freely on Poly- 

 gonum aviculare (knot-grass) ; they continue to grow slowly 

 until they are somewhat more than an inch in length, when 

 they retire for the winter, concealing themselves among the 

 stems of grasses, which appear to be their favourite resort. 

 The larva now is long and slender, and rests on the knot- 

 grass, attached by its claspers only, the body being held 

 semi-erect ; a slight bend occurs at the ventral claspers, and 

 another at the third pair of feet, the intervening segments 

 forming an elliptic arch ; the head is porrected on a plane 

 with the body, and the three pairs of feet are directed for- 

 wards, but not crowded together ; when touched, shaken, or 

 otherwise irritated, the anterior segments are bent down- 

 wards and contorted until they almost form a ring : I have 

 continued the irritation until the larva has thrown itself 

 angrily from its food to the ground, and there, after making 

 various worm-like contortions, has assumed the form of a 

 ring : on such occasions it soon reascends its food-plant, 

 and then, attaching itself by its claspers, it waves its body 

 about in a wild and dissatisfied manner. Head flat, porrect, 

 exserted, of the same width as the anterior segments : body very 

 slightly incrassated from the 4ih to the 10th or 11th segment, 

 transversely wrinkled, and having a longitudinal lateral skin- 

 fold, which, by increasing the width of the larva when 

 stretched at full length, gives it a slightly depressed appear- 

 ance ; the anal flap is deltoid, its apex terminating in a few 

 bristle-like hairs, which are directed backwards. Head and 

 body putty-coloured, striped longitudinally, the stripes vary- 

 ing only in intensity of colour : a dark and very narrow 

 medio-dorsal stripe extends from the head to the tip of the 

 anal flap ; this is darker at the anal extremity, and is not 

 perfectly uniform in vndth, but expands and contracts here 

 and there in its course : this narrow stripe is intersected by 

 a median, thread-like, paler stripe, so fine as certainly to 

 escape observation without a lens : on each side of the 

 medio-dorsal stripe is a paler and broader stripe, containing 



