208 



The Orders of Insects 



narrower face, less prominent eyes, and the absence of a hinged 

 hook to the tip of the first maxilla. There are eight or nine 

 evident hind-body segments. The larvse are active and campodei- 

 form ; in some genera the cercopods are long, in others much 

 shorter; there are six ocelli on each side of the head. The Ground- 

 beetles are mostly insect-hunters, but some species devour the 

 roots of plants. The family is distributed in all parts of the 

 world. (See fig. 157.) 



Haliplidae. — The HallpUdie are a small family of beetles agreeing 

 with those immediately following in their ovoid body-form and 

 aquatic habit, but with the two preceding families in possessing 

 a suture before the backward extension of the metasternum 

 between the hind-haunches. The number of antennal segments is 



ten only. In this family the 

 hind - haunches bear large 

 plates which conceal much 

 of the ventral surface of the 

 abdomen. The larvae are 

 of elongate form, and each 

 tergite is produced into four 

 short granulose processes. 

 The family contains only 

 three genera, but one of 

 these (^Haliplus') is world- 

 wide in range. 



Dyticidae. — The Dyticida 

 or Carnivo ROUS Water- 

 beetles are a large family dis- 

 tinguished structurally from 

 the preceding families by 

 the absence of a suture 

 across the metasternum in 

 front of the hind-haunches, 

 which have no large plates, as in the Haliplidse. The feelers, 

 with eleven segments, are inserted close to the eye and the 

 base of the mandible. The hind shins and feet are broad, flat, 

 and furnished with numerous hairs. They are used as oars, and 

 in conjunction with the evenly ovoid body adapt the insects very 

 perfectly to life in the water. Eight abdominal segments are 

 visible above. The larvae are long and tapering in form with 

 large heads armed with mandibles, which are grooved for suction 

 of the juices of victims, after the manner of grubs of Neuro- 

 ptera (see p. 203). The family is distributed in all parts of the 

 world. 



Gyrinidae. — The Gyrinida or Whirligig-beetles are easily recog- 

 nised by their very short feelers, the terminal segments of which 

 are much condensed (fig. 6y), and by the modification of the middle 

 legs into oars as well as the hind pair. Each eye is divided into 



Fig. 114. — Tiger Beetle {Cicindela campes- 

 tris, L.), Europe. Magnified. 



