Cryphalus. | RHYNCHOPHORA. 429 
two of these trees, which are from twenty to thirty years old, had been 
blown over in a manner similar to that in which poplars often suffer, 
viz., they had been snapped across at about the level of their lower 
branches ; one of them had fallen iast winter, the other during the 
previous one. On both I found evidence of their having begun to 
“decay before they yielded to the storm, but the more recent one was 
still so far alive as to be attempting to throw out leaves, yet many of 
its branches had long been dead and one side of the stem was so also ; 
this I soon found to be caused by a small beetle belonging to the family 
Hylesinide. This beetle, Cryphalus binodulus, Ratz., appears not to 
have been taken in: England since its original capture by Mr. E. W. 
Janson at Highgate ; and I may observe that very few of my specimens 
present the (sexual) spines at the apex of the elytra; and that, when 
present, the spines are very small. This species, unlike Hylesinus 
crenatus, which commences its attack close to the ground, first attacks 
the branches and then advances downwards. A colony is probably 
commenced by one, or only a few pairs; but they rapidly multiply. 
There are about a dozen of the young aspen trees (Populus tremula) on 
which I find them, and of these, besides the two already mentioned, 
they have this season killed a third tree.. The leaves which it threw 
out abundantly last spring are now all black and dead, and I suspect 
that this is entirely the work of the present season. A fourth tree is 
far gone and several others are invaded. Like most of the Xylophaga 
it only attacks the bark. In the genus Hylesinus, and others of the 
family, the parent beetles make a long straight burrow, and the eggs 
are deposited more or less regularly along either side. Unlike these, 
Cryphalus binodulus makes what may be called a little irregular cavern 
rather than a burrow. This is always immediately beneath the outer 
bark, and does not penetrate to the wood. I find invariably a pair of 
beetles in each cavern, even when nearly all the eggs are deposited, or 
when the eggs are hatched ; these are laid in little confused heaps in 
the recesses of the cavern, sometimes all in one heap, generally in three 
or four, and to the number of from thirty to sixty. The larvee when 
hatched burrow without any regularity, but tend to travel in a vertical 
direction, They are footless grubs, with strong jaws, and a distinct 
head like the larve of the other Xylophaga. I found that the eggs 
laid in May had in August produced some perfect beetles, though many 
still remained in the larval and pupal states. This has also been the case 
this season with Hylesinide I have been watching, and I suspect that 
this species, like the others, does not usually come to maturity until a 
month or two later, and then hybernates before emerging. This species 
appears only to attack the living trees, and though so minute, is from 
its numbers able to cause the destruction of any tree it colonises, A 
branch is usually first attacked by several pairs, whose progeny then, 
laying their eggs in it, complete its destruction. Wherever a brood 
has been reared a wide rough crack is observable in the bark, and a 
