COLEOPTEEOTJS INSECTS. 123 



length. The colour of the upper surface is a fine 

 blue, inclining sometimes to green. The thorax is 

 nearly twice the width of the head, truncated be- 

 fore and behind, and somewhat heart-shaped ; the 

 surface rough and granular. The elytra are oval 

 and convex, covered with large tubercular points, 

 which are arranged nearly in straight lines. The 

 under side of the thorax and the sides of the abdo- 

 men are tinged with greenish blue ; the other parts, 

 as well as the legs, are black. 



The insects to which the generic appellation of 

 Carabus is now restricted is of very considerable 

 extent, including about 170 well-ascertained species. 

 They are generally of considerable size, and most 

 frequently of a dark colour, glossed with blue or 

 purple. Many of them, however, are of the bright- 

 est metallic hues, and deserving of being ranked 

 among the most ornamental of European beetles. 

 Such are C. rutilans, an inhabitant of the Pyrenees, 

 and our own C. nitens, found in heathy districts, 

 where the soil is formed of peat, in many parts of 

 Scotland and the north of England, which scarcely 

 yields to any exotic insect in the brilliancy of its 

 lustre. The principal seat of the Carabi is within 

 the temperate zones; they become rare in very 

 warm countries, and seem to disappear altogether 

 within the tropics. They are most abundant in 

 the old world, but a few have likewise been observ- 

 ed in the northern and southern extremities of Ame- 

 rica. Britain possesses about sixteen species, and 



