Onthophagu*.] I.AMEKUCOUNMA. 11 



Tlie larvae of Onthophagus, like the perfect insect, are found in dung, and are very 

 useful scavengers ; the female forms a separate mass of dung for each larva, about tin- 

 size of an acorn, and buries it at a greater or less depth in the earth ; in this she de- 

 posits an egg, and closes the opening ; in about ten days the larva hatches, and 

 begins to devour its abode, and in about two and a httlf months reaches its full size, 

 and changes into a pupa ; the pupal state only lasts for a short time ; the larvae are 

 white, with the head yellowish, sometimes with a longitudinal greyish streak on the 

 front part of the body, subcylindrical from the head to the middle abdominal seg- 

 ment, and then somewhat gibbous to the sixth segment, which is furnished with a 

 prominence on disc that is used by the larva for locomotion ; from thence to apex the 

 body is curved downwards ; the legs are rather long, and are destitute of claws, as is 

 the case with other dung-feeding species. 



Thirty-three species of the genus are found in Europe, of which 

 seven occur in Britain ; although they are easily recognized if compared 

 together, yet the descriptions usually given by Erichson and Thomson, 

 &c., are in one or two cases somewhat hard to work species out by, and 

 a little apt to cause confusion. 



I. Colour unicolorous black. 



i. Head with one or two horns in male ; length 5-10 mm. 



1. Head with two horns in male ; thorax punctured . O. TAURUS, L. 



2. Head with the vertex in male prolonged into a 

 plate terminating in a long horn ; thorax punctate- 

 granulate O. NUTAN8, F. 



ii. Head with a transverse raised ridge in male ; length 

 4-4J mm O. OVATCS, Z. 



II. Elytra yellowish-testaceous or fuseo-testaceous, either 

 almost unicolorous or with more or less pronounced 



dark markings ; head with a horn on vertex in male. 



i. Elytra with dark markings very cloudy and indis- 

 tinct, and, as a rule, almost unicolorous testaceous . O. COJSOIUTA, Herbtt. 



ii. Elytra with dark markings distinct. 



1. Head and thorax bronze-green or coppery ; dark 



markings on elytra not, or scarcely, reticulate. 



A. Sculpture of thorax more or less granulate ; 

 average size larger ; pygidium more distinctly 



punctured O. VACCA, L. 



B. Sculpture of thorax asperate-punctate ; aver- 

 age size smaller ; pygidium more obsoletely 



punctured O. FBACTICORNIS, Prey*. 



2. Head and thorax black, with very slight bronze 

 reflection ; dark markings on elytra more or less 



plainly reticulate O. NUCHICORNIS, /.. 



O. taurus, L. Black, rather dull, sometimes with a slight greenish 

 metallic reflection on thorax ; head rather long, semi-ovate, with a raised 

 margin, rugosely punctured ; antenna? reddish, with blackish club ; 

 thorax rounded at sides and base, with anterior angles blunt, rather 

 diffusely and not strongly punctured ; elytra with feeble and obsoletely 

 punctured striae, the interstices dull, sparingly punctured and sha- 

 greened ; legs blackish or dark reddish-brown. L. 7-10 mm. 



Male with two long horns on vertex of head, which are curved and 

 divergent. 



