LAMELLIOORNU. 13 



tinct, and often almost wantiiig, so that the elytra appear unicolorous ; 

 head rather long with strong raised margin ; antennae reddish with 

 blackish club; thorax rounded at base and sides, slightly sinuate before 

 anterior angles which are strongly projecting, very thickly and asperately 

 punctured ; elytra with very shallow striae, which are obsoletely punc- 

 tured, interstices broad sparingly and rather distinctly punctured ; legs 

 black with tarsi somewhat ferruginous, posterior tibue with apical 

 setae unequal. L. 4-6 mm. 



Male with the head sparingly punctured, and the vertex raised into a 

 plate at buck, terminating in a more or less curved horn ; thorax 

 reflexed in front, simple. 



Female with the head more closely punctured and furnished with two 

 transverse keels, the one at back of vertex being rather strongly raised ; 

 thorax reflexed, slightly projecting in middle of apical margin. 



In dung ; generally distributed and common in the London district, and the 

 greater part of the south of England, but much less common further north, and not 

 apparently recorded from the northern counties or from Scotland; Swansea ; Bath ; 

 Meed wood Forest ; Bepton, Burton-on-Trent. 



O. vacca, L. Head and thorax dark bronze-green or coppery, 

 rather dull, elytra testaceous or reddish-testaceous with distinct irre- 

 gular dark-green markings, which in an ordinary light often appear 

 almost black ; head rather large, strongly margined, varying in the 

 sexes ; antennae red with blackish club ; thorax finely and rather 

 thickly granulate, a character which is usually given as distinguishing 

 the species, but is unsatisfactory, as the punctures on the thorax of the 

 allied species are asperate, and give the upper surface a granulate 

 appearance ; the base and sides are rounded, and the latter are not 

 sinuate before the anterior angles which are obtuse ; elytra with shallow 

 and very obsoletely punctured striae, interstices finely granulate in 

 irregular rows ; legs black, tarsi dark ferruginous ; the species is vari- 

 able in size, but on the average is larger than any other of our British 

 species. L. 7-10 mm. 



Male with the head elliptical in front, with the vertex extended into 

 a sloping plate, dentate on each side, and terminating in an erect spini- 

 form horn ; thorax reflexed in front, sinuate in middle of apical 

 margin. 



Female with the head round in front, and furnished with two trans- 

 verse keels, the hinder of which is more elevated and more or less 

 distinctly raised into a short horn at each side ; thorax reflexed in front, 

 with a slight prominence in middle of apical margin which is more or 

 less distinctly bituberculate. 



In some small males the plate 011 vertex is small and terminates in an 

 abbreviated horn, and the thorax is shaped as in the female. 



In dung ; local ; generally distributed and common in the London district, Kent, 

 Surrey, and the grvater part of the south of England ; Brent Knoll, Soon-net, in 



