of Buprestidae and Elateridse. 179 



series of forms as those of Cerambycidse, but in a less degree. In 

 these latter the collar of the prothorax varies not a little in ex- 

 tent according to groups and genera, the head being in some cases 

 deeply inserted into the prothorax, in others tolerably free ; but, 

 in all of them, so much at least of the principal portion of the pro- 

 thorax remains that, at any rate on the underside, it appears as a 

 transverse fold which carries the short legs when such are found. 

 To the larvse of Lamise correspond those of Buprestidse, to that of 

 Trachys the larvae of Lepturini, in which the ^ead is sometimes 

 so little inserted that it seems to betray a relationship to those 

 larvae of Curculiones which burrow in timber. When the head 

 occupies such a position as in the larvae of Buprestidae, being 

 inserted in the prothorax, the skin of the neck must necessarily 

 be very full, in order to afford the necessary play for the pro- 

 trusion and retraction of the head; and in proportion as the in- 

 sertion of the head is deeper, the skin of the neck is fuller and 

 more protruding. 



It will now appear that although none of the theories above 

 mentioned have hit upon the facts, they all contain in some way 

 an element of truth. Low's view is purely anatomical, and 

 although wrong in a morphological sense (because the mandibu- 

 lar muscles cannot well be situated in the prothorax of any insect 

 with articulating mandibles), yet it is so far true that the head 

 which contains them is itself imbedded in the prothorax; what 

 Low has overlooked is the walls of the head. Goureau's view 

 is, so to say, that of common sense unshackled by anatomical 

 or morphological scruples ; and from such a point of view the 

 prothorax might be called the head with perfect justice. Erich- 

 son's view is learned and critical, with a theoretical element 

 inviting attention, but is neither probable in a physiological 

 point of view nor true in point of anatomy ; it has therefore less 

 of body or soul than either of those it attempts to reconcile. 

 What he considers the hind part of the head is merely the dis- 

 tended skin of the neck. 



III. 



The striking external similarity between the larvae of Melasis 

 and those of the Buprestidae has not only served as a principal 

 argument for looking upon Melasis as a connecting link between 

 Elateridae and Buprestidae, and thus exercised a decisive influence 

 on all the more recent attempts at a new classification of the 

 Sternoxi, but it has at the same time weighed heavily against 

 the probability of finding in the study of the larvae a sure guide 

 to the true classification of insects — a circumstance which Ericn- 

 son has not omitted to mention in the introduction to his in- 

 structive treatise on the larvae of Coleoptera (in Archiv f. Natur- 



13* 



