NORTH AMERICAN COLEOPTERA. 279 



THE SPECIEi^ OF DINEUTES OF AMERICA 

 ]\ORTII OF MEXICO. 



BY CHRIS. H. ROBERTS. 



The .similarity in general ap])earance of the species of this genus, 

 together with the apparent lack of definite characters for their sejm- 

 ration, has not made them favorites with collectors or students. Dr. 

 LeConte monographed the species of the United States, in 18(i8, in 

 the " Proceedings of the Academy of Natural Sciences of Philadel- 

 phia," and described two new ones, serrulatus and carolimt><. In 

 1878, in the "Proc. Amer. Philos. Society," he described angustns. 

 In the " Annals of the Entomological Society of France," 1882 and 

 1888, Dr. H. Regimbart monographed the species of the world, 

 added one new species, cuuUk, to our fauna and suppressed caroHnus 

 and angastus after examining Dr. LeConte's types. 



The examination and study t^f a large series of specimens from 

 all parts of the United has enabled me to recognize all the previously 

 accepted species, and to discover three undescribed. I am also con- 

 vinced, contrary to Dr. Regimbart's conclusions, that carolinus and 

 angvstns are good species, and I hope by means of the table, descrip- 

 tions and plates, to make all the species readily recognizable to the 

 student and general collector. 



The species are all of fair size, some quite large; all are more or 

 less oval and convex. The upper surface is usually shining and 

 bronzed, and is finely I'cticulate in all except suhlineatus, where it is 

 more nearly granulate. The shape of the apices of the elytra and 

 the structure of the anterior tibitis and femora are the more impor- 

 tant characters used to separate the species, but color of the upper 

 and under surface, the distinctness of the strise and the depressions 

 of the elytra are also of use. The male genitalia afford excellent 

 characters, and the different forms are shown on the plate, but I have 

 not made use of them in the descriptions as the examination of then) 

 requires a partial dissection of the specimens. There is a difference 

 in the depth of the thorax, as compared with its width, in some 

 species, but the character does not seem to be of much value. A 

 careful examination of the under surface of the abdomen has failed 

 to show any secondary sexual charactei's in either male or female, 



TRANS. AM. ENT. SOC. XXII. JULY, 1895. 



