176 Prof. J. C. Schiodte 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-rauscles 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 larvae of Buprestidge 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- 

 neral truths, is mainly due to Prof. Erichson (in Archiv fiir Natur- 

 geschichte, 1841, i. 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 Buprestidse. Before him Low had 

 turned attention to the matter, asserting (in Entomologische 

 Zeitung Stettin, 1841, p. 35) that the larvse of Chalcophora, ''as 

 those of all Buprestidse, 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 skin. 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 



