1466 The Zoologist— December, 1868. 



The larva is found, from June to September, exclusively on the 

 alder; at first it eats boles in the leaves; it afterwards attacks the 

 edges of the leaves, and goes on until there is nothing left but the 

 principal nervines and one little piece in the middle : fig. 5 represents 

 a leaf entirely eaten out in this manner. The larva is found generally, 

 but certainly not, as stated by Klug, always, on the under side of the 

 leal ; on the contrary, 1 remember walking in a lane with alders on 

 either side, and seeing as I went along more than twenty larvae of 

 Selandria ovala on the upper sides of the leaves, their white appear- 

 ance rendering them very conspicuous. It has not hitherto been 

 discovered where the eggs are deposited, and I have not been able to 

 find any, which, however, can only be attributed to my living in town, 

 for from the large number of sawflies, which are frequently found in a 

 comparatively small area it would surely not be difficult for any one 

 living in the country to clear up this point. I expect the eggs are 

 deposiied singly in the petiole or the veins of the leaves, as the larvae 

 are always found at some distance from each other. 



The larvae are generally found when they are full grown, as they are 

 then very conspicuous on account of their white appearance, which 

 contrasts strongly with the green leaves. They seem at first sight to 

 be entirely while, but they are merely covered with a substance which 

 appears to the eye like while wool : on rubbing off this substance the 

 body is fi und to be of a very pale bluish green. Fig. "2 represents a 

 hall-grown larva immediately alter moulting, and when the woolly 

 covering has not yet made its appearance. Its head was somewhat 

 bluer than the body, but there was no spot on the vertex : on removing 

 the white covering from the full-grown larva it is found to have twenty- 

 two legs, the thoracic legs being pale green with brown claws; the 

 body is bluish green, with a darker bluish stripe running along the 

 dorsum. The head is yellowish green-brown on the vertex, and lias 

 black spots at the sides, in which the eyes are inserted; the head is 

 thinly clad with fine hairs; the mandibles are brown at the tips. It 

 appears, however, that the head is not always coloured in accordance 

 with the above description, as I found in the case of a larva which I 

 removed from the cocoon, the head of which is represented at fig. 3; 

 in this case the head was olive-green, being darker posteriorly and on 

 the vertex. According to De Geer a large circular black spot should 

 be found on the top of the head. 



The larva attains a length of -2-5 centimetres. De Geer is very cir- 

 cumstantial in his description of the white excretion, which he com- 



