24 COLEOPTERA. 



The long palpi and short clubbed antennae will at once dis- 

 tinguish the beetles of this family from the Dytiscidce. Their 

 larvae feed on other insects, but the beetles are much less voracious 

 than the Dytiscidce, and feed to a greater or less extent on vegetable 

 matter. 



One of our largest water-beetles is Hydrophilus Piceus, Linn., 

 which is more than an inch and a half in length, though narrower 

 and more convex than the species of Dytiscus. It is sometimes 

 called the Great Water Beetle, and sometimes the Harmless Water 

 Beetle. Hydrous Carcibo'ides, Linn., is a much smaller insect, not 

 measuring quite three-quarters of an inch in length ; but it is 

 shorter and broader in proportion than Hydrophilus. Both these 

 species are black and shining, and are found in stagnant water. 



The remaining species of this family are of small size (mea- 

 suring a quarter of an inch in length and under), and are of little 

 special interest. They are found in stagnant water, among the 

 roots of plants, or else in damp marshy places, close to water. 

 Hydrcena Riparia, Kug, measures less than one-twelfth of an inch in 

 length. It is brown, with reddish legs and antennae, and strongly 

 punctured. It is found among water-plants, or under stones by 

 the side of small streams. Its palpi are of extraordinary length, 

 more than twice as long as the antennae. 



FAMILY II.; 



Shape oval or nearly round ; first joint of the tarsi longer than 

 the other joints ; thorax narrowed in front. 



A few of the species of this family live in running water, but 

 the greater part are met with in damp places, in dung, or in 

 fungi. The family is not very extensive ; and the species are of 

 small size. They are generally of a black colour, more or less marked 

 with red. 



One of our largest and prettiest European representatives of 

 the group is Sphceridium Scarabceoides, Fabr. It measures a quarter 

 of an inch in length, and is black, with a blood-red spot at the base 

 of the elytra, and a large yellow spot towards the extremity of 

 each. It is met with in fresh cow-dung. 



SECTION III. BRACHELYTRA. 



Tarsi variable; palpi four; antennse short; elytra generally very 

 short, with a straight suture ; wings ample, folded beneath elytra. 



