NORTH AMERICAN GEOTRUPINAE — ^HOWDEN 233 



6. Dorsal annulets of abdominal segments 6 to 8 with a transverse patch of setae; 

 7 or 8 stridulatory teeth on the fused trochanter-femur and 1 tooth on the 

 tibiotarsus of the reduced metathoracic legs; epipharynx in front of phoba 

 with a single sensilla well isolated from either setae or row of sensilla at the 



base of the phoba (pi. 8, fig. 4) egeriei Haldeman 



Dorsal annulets of abdominal segments 6 to 8 lacking a transverse patch of 

 setae; 9 to 11 stridulatory teeth on the fused trochanter-femur and 5 to 8 

 small teeth on the tibiotarsus of the reduced metathoracic legs; epipharynx 

 in front of phoba without a single sensilla isolated from the row of sensilla 



at the base of the phoba (pi. 8, fig. 7) hornii Blanchard 



(The larvae of G. opacus, semiopacus, splendidus miarophagus, and balyi are 



not known to the writer.) 



Geotrupes opacus Haldeman 



Geoirupes opacus Haldeman, 1853, p. 362 (type, LeConte collection, MCZ), — 

 Jekel, 1865, pp. 533-594.— Horn, 1868, p. 318.— Blanchard, 1888, p. 110.— 

 Blatchley, 1910, p. 939.— Dawson, 1922, p. 196.— Bradley, 1944, p. 112. 



Geotrupes haldemani Jekel, 1865, p. 593. — Horn, 1868, p. 318. 



Geotrupes chevrolati Jekel, 1865, p. 593. — Horn, 1868, p. 318. 



Length 11 to 17.5 mm., greatest width 7 to 11 mm. 



Color of dorsum dull brown to black, sometimes with traces of blue 

 or green along margins of pronotum, elytra, and in some coarse 

 punctures. Dull coloration is due to finely alutaceous surface of 

 dorsum. Ventral surface black, sometimes with traces of bluish 

 iridescence. Legs black. Antenna and antennal club usually piceous. 

 Clypeus, eye canthus, and vertex rather finely densely punctured 

 except on the tip of the rather pronounced clypeal tubercle. The 

 tubercles near the eyes vaguely indicated. A distinctly indented 

 narrow line runs from the middle of the vertex forward to the clypeus, 

 where it bifurcates and runs along the posterior edge of the clypeus 

 almost to the outer margins. Clypeus margined, varying greatly in 

 shape, generally evenly rounded, but sometimes sharply arcuate 

 either anteriorly or laterally. No other structural differences appear 

 constantly correlated with these variations. The margined eye canthi 

 are also rather variable in shape, but usually evenly arcuate and 

 form a moderately obtuse angle with the clypeal edge. Pronotum 

 completely margined, quite convex, but with considerable variation 

 in the cm*vature of the lateral margins. Coarse punctures scattered 

 over most of pronotum, most pronounced laterally. A line of coarse 

 punctures may be present along the pronotal midline, and a small 

 circular punctate depression is usually present laterally. Minute 

 secondary punctures are sometimes present, scattered over entire 

 pronotum. Scutellum usually coarsely punctured, roughly triangular 

 with sides arcuate. Elytral striae obsolete, usually indicated only 

 by somewhat irregular rows of coarse punctures. Elytral margin 

 narrow, slightly wider anteriorly. 



