40 LAMELLICORN1A. [GWfM/ inn. 



GEOTRUPINA. 



Tle species belonging to tliis tribe are, as a rule, of large size and 

 rounded convex form; in some species the males have the thorax, and 

 sometimes the head, armed with horns and tubercles; the antennae are 

 11-joiuted, and terminate in a 8-jointed club, which is variable in form; 

 the ventral segments are six in number, and the pygidium is covered by 

 the elytra; four genera are found in Europe, of which two occur in 

 Britain; three or four other tribes intervene between the Aphodiina and 

 the Q-eotrupina, of which the Hybalina and Hybosorina occur in Europe, 

 but are not represented in our fauna. 



I. Antennae with club longer than funiculus, not lamellate ; 



posterior angles of thorax right angles ; size smaller . . . ( )I>O\T KTJ. Kim/. 



II. Antennae with club shorter than funiculus, lamellate ; pos- 

 terior angles of thorax obtusely rounded ; size larger . . . GEOTRTTPKS, Lnfr. 



ODONT2EI7S, Klug. 



The three or four species that form this genus have been by many 

 authors included under the genus Bolboceras, Kirby, which contains 

 upwards of a hundred species that are widely distributed throughout the 

 world; the species belonging to Odontceus proper have been described 

 from North America and Europe, and appear to be distinguished by 

 having the eyes entirely divided instead of only partially divided as in 

 Bolboceras; the single European species is extremely rare in Britain, 

 and may be at once known from Geotrupes by its smaller size, the long 

 club of the antennae, the right angled posterior angles of thorax, and the 

 long recurved moveable horn on the head of the male; it lives in dung, 

 but has usually been taken in Britain on the wing. 



O. mobilicornis, E. (armiger, Scop. ; ? licolor, F.). Short oval, very 

 convex, upper surface glabrous, colour black or pitchy, occasionally, in 

 immature specimens, fenuginous, under-side reddish or brownish-yellow, 

 clothed with yellowish pubescence; head thickly and rugosely punctured 

 in front; thorax punctured, with a fine longitudinal channel in centre 

 which is abbreviated in front, posterior angles right angles; elytra with 

 strong punctured striae, interstices impunctate or almost impunctatf; 

 antennae and legs yellowish, tibiae darker, front tibiae with eight teeth. 

 L. C-8 mm. 



Male with an elongate, curved, moveable horn on forehead; thorax in 

 front horned and foveolate on each side, and furnished with two teeth in 

 the centre. 



Female with two feeble prominences on forehead, and three on the 

 front of thorax. 



In small males the horn on forehead is much shorter, and the horns 

 and foveae on thorax are more or less obsolete. 



