The Scottish Naturalist. 297- 



situated on the blades, although they may project over the mid- 

 rib. The usual length of the galls is about 4 lines. Frequently 

 there may be observed on the upper surface of the leaves, min- 

 ute round reddish points, — these I take to be abortive galls. I 

 have only hitherto found galls on Salix purpurea ; but probably 

 they will occur on other smooth-leaved sallows also. 



The eggs are deposited during May, just as the leaves are be- 

 ginning to burst forth ; and the galls increase in size in many 

 cases along with them. The egg does not differ from that of 

 Vallisnieri, nor from that of any other gall-making saw-flies that 

 I have seen. 



The larva when young is rather slender, the body glassy 

 white, except when the contents of the food-canal give it a 

 greenish tinge. The head is of a light fuscous-brown, and is 

 covered with a few hairs ; the eye-spots deep black ; mandibles 

 brown, darker at the apices. 



It remains of this colour till it has become full-fed, and is 

 about to quit the gall. The head is then rather small, narrower 

 than the second segment, flattish in front, and of a grey colour, 

 with a tinge of green. Eye-spots black, and a dark irregular 

 oval spot is placed between the eyes, near the top. The man- 

 dibles are deep brown, with the palpi white. The feet are gray- 

 ish-white, with brown claws ; the fourteen claspers are of the 

 same colour as the body, but lighter. The body is attenuated, 

 cylindrical, tapering in width towards the anus. Its colour is a 

 shining orange-slate, varying somewhat in different individuals, 

 The segments are well marked, as they project in ridges, and 

 each is divided into three folds. 



I have a note of some specimens having a black mark over 

 the anal segment, and of another with the same segment 

 orange while it was young. The larvae remain in the cocoons 

 till the middle of April, when they change to pupae, and pre- 

 vious to this the colour becomes much paler. Length 6-7 lines. 



Pupa. — On the 26th April I opened one of the cocoons, and 

 found a pupa inside. It was white, with a faint tinge of green ; 

 the eyes red. On 5 th May the thorax was yellowish, the eyes- 

 deep black, mouth brownish, wings white ; the feet and antennae 

 of the same colour, but much more translucent. 



The larvae inside the galls remain curled up somewhat like 

 the form of a J. The frass is of a coffee-brown colour, and is- 

 very fine and dry. They do not make a hole for its expulsion 

 like the larvae of N. Vallis?iieri 1 but on the other hand they do 



