THE CARXH'OROVS WATER-BEETLES. 309 



which live entirely on trees, and seek their prey at night, remaining during the day concealed 

 in the folds of curled-up leaves. One large section of Truncatipeiinse, however, are terrestrial insects, 

 such as the Artillery-beetles (Brachininse), Odacanthinse, and other sub-families, and another (Copto- 

 derinpe, Thyreopterinse) are bark-insects, i.e., specially adapted for seeking their prey upon or under- 

 neath the bark of trees, where lignivorous and fungivorous insects of other tribes abound. The feet 

 of these are not lobed, but their claws are in many genera finely toothed, a structure which enables 

 them to maintain their foothold in running over the bark. Many run with great speed, and, owing to 

 their flattened forms, slip with facility under slightly-loosened bark in pursuit of their prey. A large 

 number of brilliantly-coloured and prettily-marked species, belonging to these sub-families, inhabit the 

 forests of tropical countries. 



Among the remaining families of Truncatipenna;, the most conspicuous insects for size, strength, 

 and truculent aspect are the Anthise, which abound in open districts in most parts of Africa. They 

 are essentially runners, their wings being rudimentary or absent, and they are reported to seek their 

 prey with great activity among low bushes and herbage in sandy places. The truncature of the wing- 

 covers is sometimes scarcely perceptible in this group. More than 100 species are known, grouped 

 under eight genera. Our illustration represents a species common in South Africa, especially in Natal. 



CHAPTER III. 

 CARNIVOROUS, ANOMALOUS, AND BURYING-BEETLES. 



PENTAMERA (continued) Family DYTICID.E, or Carnivorous Water - Beetles Air-breathing Insects Peculiar Mode of 

 Respiration Structure, Transformations, and Habits Family GYRINHXE, or Whirligig Beetles Curious Mode of 

 Progression on the Surface of the Water explained Family PAUSSID.E Grotesque Forms Kept as Involuntary 

 Guests of Ants Tribe PALPICORNIA Family HYDROPHILIIXE, Herbivorous Water-Beetles Carnivorous Habits of 

 the Larvae Families GEORRYSSID.E, PARNID.E, and HETE:IOCERID.E Mode of Breathing by Air-bubbles carried 

 beneath the Water by the Parni Tribe BRACHELYTHA : Family STAPHYLINID.E Low Type of Structure Families 

 PSELAPHID.E and ScYDM.ENiD.E^Blind Pselaphidse, the Pets of Ants Tribe NECROPHAGA or CLAVICORNIA Hetero- 

 geneous Composition of the Tribe Family SILPHID.E Burying Beetles, and their Singular Habits Families 

 TRICHOPTERYGID.E, SCAPHIDIID.E, PHALACRID.E, and XITIDULID.E The Smallest Beetles known Families TROGO- 

 SITID.E to HISTERID.E End of the Xecrophaga. 



FAMILY DYTICID^E. 



THE Dyticidse are predaceous Beetles of the water, differing from Carabidse chiefly in their legs, and 

 the shape of their bodies being modified to suit their aquatic life. The oval, or boat-like, and compact 

 general form and oar-shaped hind legs of the typical species are familiar to all young naturalists, as 

 many species are amongst the most common living objects of our ponds and slow-flowing rivers. The 

 principal other points in which they differ from Carabidas are, (1) their smooth antennae, destitute of 

 minute sculpture and fine pubescence, which constitute the sensitive surface in those organs ; (2) the 

 greater development and more solid texture of their ligula, or tongue ; and (3) the larger dimensions 

 of the coxae of their hind legs, which are in the typical genera soldered to the voluminous metasternum, 

 or hind portion of the breast. With regard to these differences, it may* be said that the smoothness of 

 the antennai is a necessary condition of their aquatic life, as a hairy surface under water would interfere 

 with the free transmission of impressions through the organs, by the collection of air-bubbles on their 

 surface. The great development of the hind coxae, their consolidation with the metasternum, and the 

 great volume of the latter, are in similar manner correlated to the increased work thrown on the 

 hind legs, as oars, in propelling the insect through the denser element of water, stronger muscles, with 

 firmer attachment surfaces, necessitating increased size and firmness of the segments of the body to 

 which their legs are articulated. 



Dyticidae are most abundant in stagnant waters. When inactive, or hibernating, they conceal them- 

 selves in the thick tufts of aquatic herbage, or in the soft mud. They become active in the early 

 spring, and may then be seen moving in the water by the propulsion of their strong hind legs, and 

 coming at intervals to the surface to breathe. This function, indispensable to them as air-breathing 

 animals, is performed by elevating the tips of their bodies on arriving at the surface, and taking in a 

 supply of air for the stigmatic openings of their abdomen and thorax, under the tips of their wing- 



