STUDIES IN THE AMERICAN BUPRESTIDiE 49 



considered a special tribe based upon the position of the antennal 

 fossae and distinguished from others, such as Chrysobothris, by the 

 form of the elytral bases, degree of separation of the eyes and other 

 characters. Many genera were unnecessarily rejected by Lacordaire, 

 presumably because of deficiency in structural peculiarities affecting 

 those special organs usually looked to elsewhere, or in diversification 

 of the sclerites of the under surface, overlooking the fact, of which we 

 here have sufficient proof, that our criteria for generic definition 

 should vary to fit the conditions of the particular section of the Cole- 

 opterous series that we may have under consideration. In this case 

 elytral and antennal structure become of paramount importance from 

 the generic viewpoint, although in many other sections of the order 

 they may be wholly unimportant. 



Messrs. Warren Knaus, H. F. Wickham and Chas. W. Leng have 

 generously permitted me to acquire duplicate material from their 

 collections, and this, together with a considerable series in my own 

 cabinet collected by Dunn, Levette and others, gives me a very fair 

 representation of the species. I also have to thank Mr. Champion 

 for a transcription of Ollivier's diagnosis of Buprestis viridula. In 

 order to study the laws of intraspecific variation I obtained extensive 

 series collected by Mr. A. H. Manee, at Southern Pines, North Caro- 

 lina, consisting of about sixty-five specimens of Buprestis ornata and 

 some twenty-five examples each of B. apricans and Dicerca obscura. 

 These have been of some utility in several efforts to decide whether 

 or not two closely allied uniques might represent different species, for 

 the laws of variation applying to a few species are very apt to apply 

 to all those in the same group of genera. The secondary sexual char- 

 acters at the apex of the abdomen are remarkably inconstant within 

 rather broad limits and cannot be employed, as a rule, in defining 

 allied species, and punctuation and general sculpture are also variable 

 in some parts of the series to a rather unusual degree; but the forma- 

 tion of the elytral apices is usually rather constant. So it required a 

 large amount of study to become sufficiently familiar with the subject 

 to attempt the definite separation of specific and subspecific forms. 

 Probably I have made some mistakes which future knowledge will 

 rectify.^ 



'This paper is the gradual outgrowth of an original intention on the part 

 of the writer, to describe, merely in an isolated manner, a few species of 

 Gyascutus. 



