COLEOPTERA 



505 



Fig. 604. 



The larvae of some exotic species are said to live in damp earth; 

 but the larva of Stenelmis bicarindtus, which was described by- 

 Professor Matheson ('14) is aquatic. This larva (Fig, 604) 

 differs greatly in form from the representatives of the two 

 preceding families figured above, being long and slender. 



The family HETEROCERID^, or the variegated 

 mud-loving beetles, includes only the genus Heterocerus, 

 of which eleven species have been foimd in our faima. In 

 this family all of the tarsi are four-jointed; the first four ab- 

 dominal segments are grown together on the ventral side ; 

 and the tibias are dilated, armed with rows of spines, and 

 fitted for digging. These beetles are oblong or sub-elon- 

 gate, oval, densely clothed with short, silky pubescence, 

 very finely punctate, and of a browm color, with the elytra 

 usually variegated with undulated bands or spots of yellow 

 color. They live in galleries which they excavate in sand 

 or mud at the margins of bodies of water, and, when dis- 

 turbed, run from their galleries and take flight. 



The family GEORYSSID^, or the minute mud-loving 

 beetles, includes only the genus Georfssus, of which only 

 two species have been found in the United States. They 

 are very minute, rounded, convex, roughly sculptured, black insects, 

 found at the margin of streams, on wet sand ; they cover themselves 

 with a coating of mud or fine sand, so that they can be detected only 

 when they move. 



The family DASCILLID^ includes certain beetles that live on 

 plants, usually near water. The legs are short, with slender tibias; 

 The tarsi are five-jointed; the anterior coxas bear a distinct trochan- 

 tin ; the posterior coxse are transverse, and dilated into a plate partly 

 covering the femora ; and the abdomen has five free, ventral segments, 

 the fifth rounded at the tip. 



Sharp ('99) states that the larva of DascUlus cervinus is subterra- 

 nean, and is believed to live on roots; in form it is somewhat like a 

 lamellicom larva, but is straight, and has a large head. 



Only twenty -one species of this family have been described from 

 our fauna ; but these represent fifteen genera. 



The family EUCINETID.^ has recently been separated from the 

 Dascyllidas. In the Eucinetidse the anterior coxce do not bear a 

 trochantin; the posterior coxae are dilated into immense oblique 

 plates, concealing the hind legs in repose; and the internal lobe of 

 the maxillae is armed with a terminal hook. Only eight species of 

 this family occur in our fatma; seven of these belong to the genus 

 Eucineius. 



The larva of a European species of Eucinetus lives on fimgoid 

 matter on wood. 



The family HELODID.^ includes small beetles, less than 6 mm. 

 in length, foimd on plants near water. As in the preceding family, 

 the anterior cox^ are without a trochantin; but the lacinia of the 

 maxillae is not armed with a terminal hook; and the cuticula of the 



