NORTH AMERICAN GEOTRUPINAE — ^HOWDEN 181 



coarsely, moderately, irregularly punctate medially, punctures be- 

 coming fine, close laterally. Minute secondary punctures evenly dis- 

 tributed over pronotum. Lower half of pronotal declivity of male 

 coarsely, sparsely punctured, more heavily and completely punctate 

 in female, Scutellum usually with onl}^ minute secondary punctures. 

 The second, fifth, and eighth elytral striae obsolete, indicated by a 

 shallow indentation or a few punctures or both. Second stria indi- 

 cated by four to eight punctures, fifth and eighth striae slightly more 

 pronounced. Punctures in striae moderate, usually separated by 

 slightly more than their own diameter; without setae. Elytral margin 

 and epipleuron each with a row of moderately long setae and num- 

 erous short setae. Metasternal prominence in front of middle coxae 

 small and only slightly elevated above plane of mesosternum. Hair 

 of underside long and moderately dense. 



Head of male with tubercles on eye canthi and clypeus moderate 

 to well developed. Horn of vertex long, not bifid at tip. Head of 

 female lacks tubercles and horn, but has carina similar to females of 

 B. farctum. Pronotal modification of male moderately to strongly 

 emarginate. Lateral limiting grooves and carinae moderate. In 

 female the transverse carina is less developed and evenly arcuate. 

 The lateral carinae and limiting grooves only barely indicated. 



Genital capsule of male short and blunt, about 1.5 times as long 

 as wide, tipped with long setae. Genital capsule is very different 

 from that of B. conjusum, which is much more elongate. 



Variation in the specimens examined is slight. The species can be 

 easily distinguished by the almost circular postmedian elytral spot, 

 the median dentiform point of the black border of posterior pronotal 

 margin, the male genital capsule, and pronounced horn and tubercles 

 of well developed individuals. 



B. biplagiatum was mentioned by Brown (1927, p. 27) as occurring 

 with other species in pastures and old sandy roads. He reiterates 

 later (1928, p. 192) that the species is colonial, occurring in mixed 

 colonies with other species. 



Adults have been collected occasionally at light and are active from 

 May until October. At no time are they common, but appear to be 

 more numerous in the fall. 



Specimens examined: 25 males, 26 females. 

 KANSAS: 14 males, 14 females. Clark County, Douglas County, Larned, 



Medora, Norton County, Rush County; (2) May, (2) June, (1) July, (2) 



August. 

 NEBRASKA: 1 female. Cambridge; (1) August. 

 OKLAHOMA: 10 males, 8 females. Payne County, Noble County; (1) May, 



(1) June, (6) September, (10) October. 

 TEXAS: 1 male, 3 females. Dallas. 

 WISCONSIN [Paratype, male, from literature. Trout Lake (Vilas County).] 



