172 THE ENTOMOLOGIST. 
length been thrown upon this matter. In this confusion the 
present species has only been involved as regards that variety 
of the male insect which is entirely black, the red-banded 
form having already been recognised by Fabricius as a distinct 
species. 
I have already given a figure of the larva of Sylvarum 
(vol. v., 2nd series, page 70, pl. 4, fig. 8), only, however, for the 
purpose of calling attention to the points of difference between 
it and the larva of Lucorwm, and without any reference to its 
metamorphosis. I have since received another larva from Dr. A. 
J. van Rossum, from which I am enabled to give a description of 
its metamorphosis after having had to wait a long time for 
the appearance of the imago. My description is, however, still 
imperfect, the egg and even the pupa being wanting. The first 
is, in all probability, deposited in a wound made by the saw 
of the female in the bark of a twig or petiole of the birch, and is, 
probably, either colourless or of a pale green tint. 
I am also unacquainted with the earliest stages of the larva. 
Zaddach, however, informs us that its whole body is covered with 
a white powder, excepting in the middle of the dorsum at the 
place where, later, the beautiful blue dorsal line makes its 
appearance, the first trace of which is a little fine black line, 
visible after the second moult. ‘The first of the two larve which 
Ihave had in my possession (it may be taken as a proof of the 
rarity of the species in the Netherlands that I have only been 
able to obtain two) was found on a birch tree near Noordwijk in 
the beginning of October, 1858, and from this was reared the 
dark-coloured male which I have figured. ‘This larva is repre- 
sented on the plate already referred to in the fifth volume, and on 
the present plate 3, fig. 5. 
The other larva was sent to me from Enschede by Mr. van 
Rossum; it was among some other Cimbex larve which I 
thought at the time must be referred to Cimb. sorbi, Zadd., 
in which, as it afterwards appeared, I was mistaken. Mr. van 
Rossum had mentioned to me in his letter that he sent two 
species, so that he had clearly distinguished the larva of 
Sylvarum. ‘The larva received from Enschede (figs. 1 and 2) was 
greener and less yellow than that found at Noordwijk. Both 
had the usual form of the larger larve of this genus, resting 
during the day-time rolled up on the under side of a leaf, and 
