PHYLOGENT. 



35 



noteworthy in the face of the statement made by certain 

 authors that the Coleoptera were originally derived from a wood- 

 boring insect, and that it was this habit that brought about the 

 development of the hard-textured elytra. 



As there are absolutely no connecting links of any value, the 

 question of the original ancestor of the order is only a matter of 

 mere hypothesis. Scudder believes that it was a wood-boring 

 Palceodictyopteron, while Lameere considers it should be looked for 

 among the JNeuroptera-Planipennia, and Ganglbauer would derive 

 the order from the Orthoptera. Lameere (Ann, Soc. Ent. Belgique, 

 xliv, 1900, p. 356) is of opinion that the ancestor of the Coleoptera 

 must have had the following characters: — (1) A complete meta- 

 morphosis ; (2) four Malpighian tubes ; (3) the mouth-parts 

 adapted for trituration of food (i. e. mandibulate and not suc- 

 torial); (4) the prothorax large and free; (5) five joints to all the 

 tarsi ; (6) an onychium between the tarsal claws ; (7) three 

 ocelli ; (8) eight visible segments of the abdomen ; (9) all the coxse 

 conical and projecting ; (10) antennae with eleven joints, not 

 differentiated. 



As mentioned above, this ancestor, according to Lameere's view r , 

 must have belonged to the group of Neuroptera-Planipennia, and 

 lived under bark or bored into the trunks of trees, the advantage 

 of the change in the form and substance of the upper wings being 

 therefore evident. 



Ganglbauer (Munch. Kol. Zeitschr. i, 1903, p. 276), in alluding 

 to Lameere's hypothesis, says that, while he does not wish to enter 

 upon a discussion as to the phylogenetic origin of the Coleoptera, 

 he is still of opinion that it is more reasonable to consider them 

 as derived from one of the older branches of the Orthoptera. 



To this Lameere (Ann. Soc. Ent. Belg. xlvii, 1903, p. 156) 

 replies that if the Coleoptera are considered as descended from 

 the Orthoptera, we admit a " polyphyletisme de l'holometabo- 

 lisme"; that is to say, that we must allow that holometabolic 

 insects, or insects with perfect or very marked metamorphoses, 

 must have arisen from more than one independent source. Al- 

 though, at first sight, the argument may seem to have some weight, 

 there really does not appear to be any insuperable objection to the 

 independent origin of the orders or sections in question. But if 

 the objection be sound, we must, to begin with, divide the Neuro- 

 ptera into two distinct orders. Not that this need cause any 

 difficulty, for the insects placed by Sharp under the Neuroptera 

 are distributed in six different orders by Packard and in five by 

 Brauer. 



Since the foregoing paragraphs were written, Herr Handlirsch 

 has published his exhaustive work ' Die Fossilen Insekten.' In 

 vol. ii, p. 1278, t. vii, he shows the Silphidjs and HiSTEBiDiE as 

 the earliest beetles. These appeared in the Triassic period, and 

 from the Silphid^ at various periods there spring off the Staphy- 

 linidjE, of which the Pselaphidve are a later branch, and (in 



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