176 Prof. J. C. Schiddte on the Classification 
fixed to the firm sides of the head, but pushed back into a pecu- 
liar kind of soft bag behind the head. If anybody were to state 
that he knew of a group of Rodentia whose jaw-muscles were 
not fixed to the sides of the skull, but accommodated in a mem- 
branaceous appendage behind the occiput, the absurdity would 
be apparent to every one; but that statement concerning the 
mandibular muscles of the larvee of Buprestide implies a diffi- 
culty if possible still greater. For as their hard mandibles are 
articulated on the firm framework of the mouth by means of 
complete cardinal joints, the necessity for a firm support for the 
moving muscles is still greater than in Rodentia. The difficulty 
is, moreover, enhanced by the fact that the membranaceous part 
of the head with the mandibular muscles, when compared with 
the smaller anterior part containing the organs of the mouth, in 
shape and size appears as a larger circle placed behind a smaller 
one, from which it follows that the relative position of the base 
of each mandibular muscle and the inner angle of the mandible, 
or the point on which the tendon must join the mandible, must 
be such that a muscle thus placed could not inflect the mandi- 
bles unless the tendon went through a pulley. But such a 
pulley-arrangement would seem inapplicable where so great a 
force is required as is the case with chisel-shaped instruments 
destined in many cases to be used as pincers to detach piece 
after piece of sound timber. 
This account, which it seems so difficult to reconcile with ge- 
neraFtruths, is mainly due to Prof. Erichson (in Archiv fiir Natur- 
geschichte, 1841, 1. p. 81), and it has met with universal assent as 
the only true solution of the problem (which is certainly not 
very easy) how to interpret the peculiar-looking front part 
of the body of the larva of Buprestidz. Before him Low had 
turned attention to the matter, asserting (in Entomologische 
Zeitung Stettin, 1841, p. 35) that the larvee of Chalcophora, “as 
those of all Buprestide, are distinguished by the extension of 
the prothorax, which is rendered necessary for the reception of 
the enormous mandibular muscles.” Low, therefore, agreed 
with Ratzeburg in assuming that not the head, but the pro- 
thorax, was divided into two parts, of which the anterior part 
was soft, the posterior endowed with hard skm. Against Low, 
Erichson urged the great anomaly of the mandibular muscles 
being placed in the prothorax ; and it seems that this considera- 
tion more than any other has led him to the new interpretation 
which is now generally adopted ; for in favour of this he appealed 
to the fact that the muscles in question did not, as Low thought, 
fill the whole prothorax, but only its anterior soft portion, which 
he therefore considers to be part of the head, while he considers 
that part of the body which Ratzeburg and Low looked upon as 
