DYSCHIRIUS DYTICID^E. 



347 



rose-chaffer. See CETONIID^:. Other gigantic insects 

 are inhabitants of tropical regions, to whose entomo- 

 logical fauna they impart a very decided appearance. 

 None arc found in this country, and only one in 

 France. The larger kinds are found in Guiana, 

 India, &c* ; those, however, found in more moderate 

 climates, as in China, in the neighbourhood of Buenos 

 Ayres, &c., are generally of smaller size. 



According to M. Lacordaire, whose researches in 

 entomology in South America have been very exten- 

 sive, the habits of the various species are nearly alike. 

 During the day they conceal themselves in holes in 

 the ground, or on the decaying trunks of trees ; or 

 they may occasionally be seen creeping about the 

 footpaths in forests. At the approach of night they 

 quit their retreats, and fly about the trees in the 

 same manner as our Mclolontha vulgaris and solstituills. 

 M. Lacordaire supposes that it is then that they take 

 their food ; but analogy would induce us to suppose 

 that, like the Melotonlhce, it is during the day that 

 they feed, and that their nocturnal flights are for the 

 purpose of seeking their mates. They produce a 

 shrill noise by rubbing an elytra against the abdomen. 

 The females are generally more common than the 

 males, and are for the most part destitute of those 

 remarkable horns which the males exhibit, and which, 

 so far as we yet know, seem to be of no use to the 

 in~(>ct as means of defence. One of the species, 



Di/nnstes let mis, is recorded by Say, the American 



i I i 



entomologist, to have occurred on one occasion in 



such numbers as to have caused no little surprise in 

 the neighbourhood of Philadelphia, where they were 

 discovered, although during eighteen years an indus- 

 trious collector had only previously met with two 

 individuals. They were found in the cavity of an old 

 cherry tree, which was blown down by the wind. 



Of" the larger and more remarkable species, the 

 Hercules and Elephant beetles may especially be 

 noticed. The former is black and polished, with 

 greyish elytra, in the males the thorax is protruded 

 into a thick and curved horn bent downwards at the 

 tip, and woolly beneath, being as long as the whole 

 body. The head is also armed with a similar but 

 shorter horn, bent upwards at the tip, so as to come 

 in contact with the former ; the entire length of this 

 curious beetle is nearly six inches. 



Dynastes Hercules. 



The fine species figured for the first time in our 

 plate of " Beetles," from the collection of the Rev. 

 I'. \\ r . Hope, F.R.S., is named by that gentleman 

 Dynamics Hardw'wkci, in honour of general Hardwicke, 

 the celebrated Indian naturalist, by whom it was 

 brought from Nepal. It is thus described by Mr. 

 Hope, in his Synopsis of Ncpalese Coleoptera, "Niger, 

 xrtt/r/ffifji.'i, thoracc fjii/ii/riror/ii, contii dapitis crecto, 

 rci'ui-ro, clytrix cusfruicix, pcdibiisque mgris." Black, 

 with a scutelhnn, the thorax with four rather short 

 horns, the head with an erect horn bent backwards 



at the tip, the elytra chestnut coloured, and the legs 

 black. It is rather more than two inches long, and 

 one inch wide. 



DYSCHIRIUS (Panzer). A genus, or rather 

 sub-genus of coleopterous insects, belonging to the sec- 

 tion Pcntamera, family Cnrabidas, and subfamily Scari- 

 tides. The species are of small size, and closely allied 

 to Clivina, from which they differ in having the" thorax 

 globose, and the anterior tibiae not, or but rarely, pal- 

 mated at the tip. They are of small size, and are 

 found in damp situations, on the sea coast, and under 

 stones, &c. ; the species, of which there are nearly a, 

 dozen British species, require a more minute investi- 

 gation than has hitherto been bestowed upon them. 



DYSDERA (Latreille). A genus of spiders, be- 

 longing to the quadripulmonariae of Latreille, having 

 six eyes placed in a curve resembling a horse-shoe, 

 open in front, the mouth-claws very large, and pro- 

 duced in front ; the maxillae straight, and dilated at 

 the place of insertion of the palpi. The type is the 

 Dysdera erytlvrina of Latreille, a species not uncom- 

 monly met with in England under stones. 



DYTICID^E. A family of coleopterous insects, 

 belonging to the section Pentamera, sub-section Adc- 

 phaga, and comprising the aquatic species of voracious 

 beetles, which formed in the Linnaean system the 

 genus Dyticus (or as it is occasionally, but improperly 

 spelt, Dytiscujs}. These insects are distinguished by 

 their oval and depressed form, the moderate length 

 and slenderness of the antennae, the structure of the 

 legs, formed for swimming, &c. An examination 

 of the external structure of the body of these animals 

 discovers a solidity of organisation of the various 

 parts, from which great strength is necessarily imparted 

 to the insects. A sternum (or breast bone, external), 

 of very large size, of which the parts are so con- 

 structed as to form a perfect piece of armour ; a pair 

 of flattened coxa?, dilated and produced into a point 

 behind (generally mistaken for the extremities of the 

 sternum itself) ; posterior legs thick and compressed, 

 and a strong fringe of hairs to all the legs, are the 

 organs which chiefly tend to enable these insects to 

 make their way through an element in which they are 

 the scourge of a mass of animals more weak than 

 themselves. They are, in fact, the aquatic repre- 

 sentatives of the equally voracious land Carabidce all 

 kinds of food seems good to them. They swim with 

 great agility, and often make their way out of the 

 water, not only towards the night, but in the hot sun- 

 shine. De Geer kept some a long time in glass vases 

 filled with water, feeding them upon flies and spiders. 

 One day one of them attacked and devoured a large 

 leach, but this food disagreed with it, as the following 

 day large morsels of the animal were discharged from 

 the mouth, and the Dyticus soon afterwards paid for 

 its gluttony with its life. Esper kept one of the 

 Dyticus marginalis in the same manner, feeding it 

 once a week, or sometimes oftener, with a piece of 

 raw beef the size of a nut, from which it completely 

 sucked the juices. It would sometimes fast for several 

 weeks together. It killed an individual of Hydrous 

 piceus, a water beetle larger than itself, piercing it 

 between its head and thorax, the only part of the 

 body not protected by the horny covering of the 

 animal. 



This family comprises a great number of species, 

 of which the'majority are of small or minute size. 

 These, of course, have not attracted so much of the 

 attention of observers as the large species, whose 



