STUDIES IN THE AMERICAN BUPRESTID^ 7I 



abdominal segment is thick, truncate and transversely excavated 

 throughout the width of the truncature in both sexes. 



Spinthoptera n. gen. 



The genus Psiloptera, of Solier, having as its type the South Ameri- 

 can attenuata, of Fabricius, as amplified by Lacordaire became very 

 composite and indefinite in its scope, a number of generic types being 

 included by him which have since been separated and held to be amply 

 valid, such as Perotis, Polybothris, Hippomelas and Ectinogonia. 

 Thus simplified Psiloptera has been continued by various authors 

 without much further amputation of members, and I have ventured 

 here to detach those forms having the prosternum truncate anteriorly 

 and not medially prolonged and the elytra studded with shallow, 

 finely punctate and pubescent metallic areolae, under the generic name 

 Spinthoptera. General facies, completely ignored by Lacordaire, is 

 of itself in reality the most important structural character prevailing 

 in this group of genera and is more decisive than modifications of 

 special organs, of which there are very few. In fact the genera might 

 be termed opinionative, in the same sense that species not character- 

 ized by striking structural differences in special organs are usually 

 called opinionative species. To maintain that either species or genera 

 are less real for being of such an opinionative nature is not justifiable; 

 it merely necessitates greater intelligence and experience in specifically 

 delimiting such series of individuals, or in aggregating such groups 

 of species to form genera, with a greater attendant risk of mistakes; 

 but after all, in the search for truth, which alone should be the ulti- 

 mate aim, errors of judgment are practically unavoidable at times. 



We note in this genus a departure in several structural features 

 from those of the three preceding genera, aside from the special and 

 peculiar modification of the antennae common to all the Psilopterids. 

 There is, for example, no terminal antennal process; the prosternum, 

 instead of being punctured or feebly impressed along the middle, is 

 remotely bisulculate, and the first abdominal segment, instead of 

 being uniformly convex medially, is here either flattened or sulcate. 

 We should note also an entire absence of the raised basal margin of the 

 pronotum and ante-scutellar sinuation of the Hippomelids, the con- 

 stant presence of two small perforate ante-scutellar discal punctures, 

 wholly unsuggested in the Hippomelids but forcefully remindful of 



