COLEOPTERA 493 



The family MELYRIDvE is composed chiefly of small or very 

 small beetles, some of which are found on flowers, and others on the 

 groimd in low, moist places. They are said to be carnivorous. They 

 var}'' greatly in form, but bear a general resemblance in structure to 

 the preceding four families, from which they can be distinguished 

 by the presence of only six ventral abdominal segments. Some 

 members of the family are furnished with soft, orange- 

 colored vesicles, which they protrude from the sides of 

 the body and which are supposed to be scent organs for 

 defence. One of our most common representatives is 

 Collops quadrimaculdtus, which is yellow-orange, with Fig. 583. 

 the top of the head and four spots on the elytra bluish 

 black (Fig. 583). This species is foimd on grasses in damp localities. 

 The family is represented in our fauna by more than three hundred 

 species. 



The family CLERID^, or the checkered beetles, includes a con- 

 siderable nimiber of predacious species which are foimd on flowers 

 and on the trunks of trees. Many of them are beautifully marked 

 with strongly contrasting colors; this has suggested the common 

 name checkered beetles for them. Frequently they are more or less 

 ant -like in form, the prothorax being in these cases narrower than 

 the wing-covers, and slightly narrower than the head. The abdomen 

 has either five or six ventral segments; the anterior coxae are conical, 

 prominent, and contiguous, or very slightly separated; the hind 

 coxae are transverse, not prominent, and covered by the femora in 

 repose; the legs are slender ; and the tarsi are five-jointed. 

 In the larval state these insects are usually carnivo- 

 rous, living under bark and in the burrows of wood-boring 

 insects, upon which they prey; some are found in the 

 nests of bees; and still others feed on dead animal matter. 

 The family is represented in our fauna by nearly two 

 hundred species. Figure 584 represents one of our more 

 common species, Trichodes nuttalli. 



The family CORYNETID^ has recently been sep- 

 arated from the Cleridae, which they closely resemble. In this family 

 the fourth joint of the tarsi is atrophied; this character distinguishes 

 these beetles from the Clerid^. About forty American species have 

 been described. 



To this family belongs the red-legged ham-beetle, Necrobia rufipes. 

 This is a small steel-blue beetle with reddish legs; it measures from 

 3.5 mm. to 6 mm. in length. It is found about dead animal matter 

 in fields and in other situations. It sometimes invades storehouses 

 and seriously infests hams. 



The family LYMEXYLID^E includes elongated, narrow beetles, 

 with short serrate antennas. Only two species have been found in 

 this country and these are rare. To this family belongs the ship- 

 timber beetle, Lymexylon navdle, of northern Europe. The larva of 

 this species was at one time a very serious pest in ship-yards, on 

 accotmt of its habit of drilling cylindrical holes in the timber. The 



