22 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 123 



somewhat more obtusely rounded anteriorly than posteriorly, length 

 to width ratio about 2.1 to 1. Body covered with fine minutely 

 reticulate microsculpture that destroys the nitidosity. Pronotum 

 subquadrate, widest before base, sides evenly, even though feebly, 

 arcuately convergent anteriorly. The pronotal apex feebly convex 

 between the apical angles when the four pronotal angles are in equal 

 focus. Pronotal and cephalic punctures moderately strong and deep, 

 rather uniform in size and density, mostly separated by about the 

 distance of their diameters. Elytral intervals distinctly punctulate, 

 scutellum similarly punctulate. Metasternal and abdominal coxal 

 lines present but fine and weak. 



Variation: The observed size range in mm is 2.19 to 2.21 in width, 

 and 4.49 to 4.65 in length. 



Male genitalia: The aedeagus is similar to that of H. elateroides in 

 general characteristics but the tegminal arms bear distinct dorsal 

 lobes medially (see Boyle 1956, fig. 137) ; also, the enclosed ejaculatory 

 duct is of a much larger diameter, and the median lobe is scarcely 

 membranous dorso-apically. The anterior end of the internal sac is 

 distinctive (see Boyle, 1956, fig. 138). 



Biology: Nothing is known of the biology of this form. 



Published illustrations: The adult is figured by Gorham, 1888 

 (1887-1899, pi. 5: fig. 5). 



Type: Not seen. 



Type-locality: Toluca, State of Mexico, Mexico. 



Distribution: Mexico: Mexico: Toluca (type-locality). Oaxaca: 

 Oaxaca, July 15 to 21. Sonora: Bokachaka, Rio Mayo, July 5. 

 United States: Arizona: type-locality of Scaeother opacus Schaeffer. 



