of Buprestidz and Elateride. 175 
anterior part carrying the organs of the mouth is chitinized, 
whilst the larger posterior part containing the mandibular muscles 
is soft and retractile within the prothorax. In some, however, 
as in the larvee of Diphucrania (New Holland), the prothorax is 
not distended ; and the larvee of Trachys, which live in the paren- 
chyma of leaves, where they excavate their burrows, are said to 
have hard dorsal and ventral shields, free head, two eyes, and 
short legs. 
Similar to the larve of Buprestide are those of Eucnemide. 
The larva of Medasis is only distinguished by the structure of 
the mouth, and by the head consisting of one piece only. The 
mandibles are not chisel-shaped, as in the larve of Buprestide, 
but short, turned outwards, with a hook on their external margin, 
close behind the point; and the other buccal organs, which 
are free in the larve of Buprestide, are in that of Me/asis repre- 
sented by a small plate serrated in front. It is said to live in fresh 
timber, forming long irregular galleries, with entirely smooth 
and even walls, a piece of the burrow being rounded off in the 
shape of a cylinder for the accommodation of the pupa. At the 
same time, exceptions occur in the group of Eucnemide as in 
that of Buprestide, the larva of Fornax madagascariensis being, 
according to Coquerel, flat, depressed, and hard, the prothorax 
not distended, the head hard, flattened in front, with a serrated 
edge, at perceptible organs of the mouth—nay, without a 
buccal orifice; the larva cress in timber, as that of Melasis. 
Entirely different from these are the larve of Elateridz. 
They are long, slender, with a hard skin, cylindrical or a little 
depressed ; the mandibles are hooked and pointed, with an in- 
terior tooth; the maxillary lobes and palpi are distinct, the 
maxille coalesced with the labium into one piece; the legs are 
short and powerful, and the last joint of the body often furnished 
with prominent teeth. They are supposed to live on vegetable 
matter, many on decaying timber ; sometimes, Poa they 
feed on the other larve they happen to fall in with. For more 
than a century the larve of Agriotes have been known as dan- 
gerous enemies of several cereals, leguminous and other agricul- 
tural plants, of which they attack the roots. 
Such is a summary of what science hitherto has taught us as 
to the history of these larve; but it is quite clear that these 
statements do not afford the materials for an accurate estimation 
of the systematic relationships of these creatures. Nay, these 
statements even contain several details which, on closer exami- 
nation, cannot but excite doubt and suspicion, and stimulate to 
new investigations. 
This: applies, in the first instance, to the statement that in the 
larvee of Buprestide the mandibular muscles are not, as usual, 
