COLEOPTERA 487 



of the prothorax and of the elytra elliptical; they measure from 

 3.6 mm. to 5 mm. in length. The Calif ornian species was found living 

 in wet moss, darkly overshadowed by bushes, at the margin of a 

 mountain stream. 



Family LEPTINID^ 

 The Mammal-Nest Beetles 



This family is represented by only three species in North America. 

 One of these, Leptinus testdceus, is a European species, but is widely 

 distributed in this country. It lives in the nests of mice and other 

 small rodents and insectivora, and also in the nests of bimible-bees. 

 Whether it is a parasite or merely a guest has not been definitely de- 

 termined ; but it seems probable that it feeds upon the eggs and young of 

 mites and other small creatures found in these nests. This beetle is 

 oblong-oval and much depressed in form, and pale yellow in color; 

 it measures from 2 mm. to 2.5 mm. in length. Specimens can be 

 obtained by shaking a nest of a mouse over a sheet of paper. 



The other two species are Leptimllns vdlidus, found in Hudson 

 Bay territory, and Leptinlllus aplodontice, found in California on a 

 rodent (Aplodontia) . 



Family SILPHID^ 

 The Carrion-Beetles 



The carrion-beetles are mostly of medium or large size, many 

 species attaining the length of 35 mm. while the smaller species of the 

 more typical genera are nearly 12 mm. in 

 length ; some members of the family, how- 

 ever, are minute. The segments near the tip 

 of the antenuce are usually enlarged so as to 

 form a compact club, which is neither comb- 

 like nor composed of thin movable plates; 

 sometimes the antennae are nearly filiform. 



These insects usually feed upon decaying 

 animal matter; some, however, feed upon 

 fungi; some on vegetables ; and a few species 

 have been known to be predacious when 

 pressed by hunger, destroying living snails 

 and insects, even members of their own spe- 

 cies ; while a few occur only in the nests of ants. 



It is easy to obtain specimens of these in- 

 sects by placing pieces of meat or small dead Fig. 575. 

 animals in the fields and examining them 



daily. There are several other families of beetles the members of 

 which can be attracted in this way. 



The larvae also live upon decaying flesh and are found in the same 

 situations as the adults. 



We have in this country more than one hundred species of this 

 family. Our larger and more familiar species represent two genera, 

 Necrophorus and SUpha. 



The burying-beetles, Necrophorus. — To this genus belong the 

 larger members of the famil}^ The body is very stout, almost cylin- 

 drical (Fig. 575). Our common species have a reddish spot on each 



