SpUXniDIAVJE.- 



-INSECTS.- 



-Lajiellicoenia. 



213 



phoroid group are often covered, and all but incon- 

 spicuous with mud. The larvse are carnivorous, while 

 the perfect insects eat plants. 



The Ehphorus aquaticus covers itself with mud, so 

 that when feeding at the bottom of a pool it can 

 scarcely be distinguished by the ferocious aquatic 

 insects, Dytiscidaj and Water Bugs, which would prey 

 on it more often than they do, were it not so curiously 

 at times hid from their search. 



The Limnius ccncus has been observed by Kirby. 

 It is found in rivulets under stones, at times covers its 

 elytra with a coating of sand, which becomes as hard 

 nearly as stone. 



Fig. 83. 



Hydrijus piceus (male)— a the mandible , b antenna. 



The largest species of the family belong to the first 

 tribe. One of these, Hydrous piceus (fig. 83), is the 

 largest water-beetle found in this country. These 

 insects are very bad swimmers, notwithstanding the 

 oar-like structure of their four hind legs. Their food 

 is principally vegetable substances, although in cap- 

 tivity they eat greedily the larvaj of other aquatic insects 

 and aquatic molluscs. They breathe by bringing their 

 heads to the surface. The insects often leave the 

 water, especially at night. The females construct 



Fig. &i. 



Spercheus emarginatus. 



a cocoon, which they attach to water plants on the 

 surface of the water. The cocoon is of a short pear- 

 shape, and of a papei-like substance. The eggs are 

 regularly arranged within, and are wrapped up in a 

 cottony substance. They are hatched in six weeks. 



The larviB are very voracioi.-. Unlike the perfect 

 insects, they only feed on vegetable life. 



The female of Spercheiis also makes a cocoon, which 

 she carries attached to her abdomen. Every nine or 

 ten days it is destroyed by the exit of the young 

 larvje. M. Cussac found that a female in six broods 

 could rear at least four himdred larva>. Fig. 84 

 represents Sperchcus emarginatus. 



Family— SPH^RIDIAD^. 



The family Spii.ffiiuDlADvE are so called from the 

 typical genus Sphceridium. They are a group of 

 roundish insects, found in the dung of animals, such as 

 horses and cows. Their strongly-spined tibiie enable 

 thera to enter the delicious mess, which to tbem is a 

 true feast. There are twenty-two British species 

 arranged in five genera, namely, Cyclonotum, Sphceri- 

 dium, Cercyon, Mcgasternum, and Cryptoplcurum. 

 Tlie species of the latter genera are very obscure 

 indeed. 



Lacordaire divides the Palpicorns into five tribes — 



I. The second joint of the four posterior tarsi long, the first 

 very short. 

 These same tarsi oar-like ; a sternal spine, Hydrophiliihs. 

 II. The tarsi not oar-like , no sternal spine, Hi/drobiiiks. 



III. Tlie first fonr joints of these tarsi short, equal, SpercJieides. 



IV. The four first joints short, the first indistinct, Ilelophorides. 

 V. Tlie first joint elongated, . . . Siihccridiuks. 



Group— LAMELLICORNIA. 



The group of Lamellicorn Beetles is a very large 

 and well-marked one, which derives its name from 

 the terminal joints of the antennae forming a lamel- 

 lated mass. If any one examines a specimen of the 

 Common Cockchafer alive, particularly if the speci- 

 men be a male, the characteristic mark of this family 

 will be seen in the terminal plates of the antenna;. 

 In the Stag Beetles, which, however, belong to this 

 great group, the terminal plates of the antenna3 are 

 only serrated (Plate 1, figs. 9, 10). The legs are 

 strong, the fore tibia;, particularly in the female, being 

 toothed. The males in many of the species are armed 

 on the head and thorax with horns, or have the jaws 

 much developed. Excepting among the Longicorn 

 beetles, larger and more bulky species are nowhere else 

 to be found among the Coleoptera. Their krva; are 

 thick and fleshy, and have the end of the body curved 

 towards the breast, so that the grub has to lie on its 

 side. These beetles live on vegetable substances exclu- 

 sively, as will be mentioned more particularly under 

 each family. In tropical climates we have the gigantic 

 Goliath beetles, and the even larger Elepliant and 

 Hercules beetles. The Sacred beetles and dung-rolling 

 tribes belong to this group, the Chafers so destructive 

 to leaves and roots. 



Family— GEOTRUPID^ {Dung Beetles). 



We now come to the family GEOTEuriD/E. From 

 the observations of Mr. Arthur Adams, that naturalist. 



