CHAMBERS'S INFORMATION FOR THE PEOPLE. 



The family of Palpicornes have the antennae 

 long, club-shaped, and leaf-like. Their feet are 

 suited for swimming. The genus Hydrophilus 

 is common in Britain, being found in ponds and 

 ditches. 



The family Clavicornes have the antennas thick, 

 and terminated by a solid mass. In their habits, 

 they are partly aquatic and partly terrestrial. The 

 Necrophorus, or Burying-beetle, is a remarkable 

 genus, so called from burying small quadrupeds, 

 such as mice and moles. They deposit their eggs 

 in the carcass, upon which the young feed during 

 their larval stage. 



The Serricornes have the antennas serrated or 

 saw-shaped, and the elytra completely covering 

 the body. The Wire- 

 ,^flfl Btow worm, which devours 

 ^^^^^ the roots of corn, often 



to a disastrous extent, 

 ' is the larva of Elator 

 : obscnrns. The genus 

 t Lampyris, or Glow- 

 worm, is remarkable for 

 the light it emits at 

 night The females 



Firefly (Lampyrii Italtca]. especially possess this 

 property. The body is 



soft, and the light resides in the last two or three 

 sections of the abdomen. The ' Death-watch ' 

 (Anobiuni] makes a ticking noise with its jaws 

 while perforating wood ; and as this is usual in a 

 sick-chamber, and is consequently apt to be heard 

 before one dies, the noise so made is held by the 

 ignorant mind to be a warning of death, hence its 

 common name. 



The Brachelytra are so called from having short 

 crustaceous wing-coverings, and are represented 

 by the single genus Staphylinus, which is fre- 

 quently seen running about garden walks. 



The Dytiscidce are aquatic in their habits. 

 Their feet are fringed with broad stiff hairs. They 

 have to come to the surface of the water to 

 breathe, as their respiratory organs are the same 

 as other insects. 



Carnivora. These beetles have been placed by 

 entomologists at the head of this order, on account 

 of the structure and development of the organs 

 which fit them for a mode of life pre-eminently 

 carnivorous. The mandibles are armed with 

 strong and powerful teeth. They are remarkable 

 for the beauty of their colours, and hence the 

 name of Tiger-beetles. They prey, even in their 

 larval state, upon other insects. The Common 

 Beetle (Cicindela campestris) is about half an inch 

 in length, of a green colour, with whitish spots on 

 the elytra, and may be seen running about in 

 sandy fields, exposed to the hottest sunshine. 



V. SUB-KINGDOM MOLLUSCA. 



The Mollusca (Lat mollis, soft) are soft-bodied 

 animals, exhibiting bilateral symmetry, usually 

 protected by an outer skeleton. The alimentary 

 canal is completely shut off from the general 

 body-cavity. A nervous system is always present, 

 and consists of a single ganglion, or of scattered 

 pairs of ganglia. 



The Mollusca may be divided into two chief 

 divisions : 



I. Molluscoida, in which the nervous system 



ISO 



always 



consists of a single ganglion, or of a principal 

 pair with accessory ganglia. Heart very imperfect, 

 consisting of a simple open tube, or entirely absent. 

 II. Mollusca (Proper), in which the nervous 

 system consists of three principal pairs of ganglia. 

 Heart always well developed, and consisting of at 

 least two chambers. 



I. The Molluscoida include the following three 

 classes : 



CLASS I. POLYZOA. 



The Polyzoa or Bryozoa. 'Animals 

 forming composite colonies, each 

 zooid of which consists of an 

 alimentary canal suspended in a 

 double-walled sac, from which it 

 can be partly protruded by a 

 process of evagination, and into 

 which it may again be retracted 

 by imagination. The mouth is 

 surrounded by a circle of hollow 

 ciliated tentacles.' Plumatella 

 repens, a fresh-water species, may 

 be taken as the type. It is a com- 

 posite animal ; each individual 

 consists of a sac with a double 

 wall. "Within this is suspended 

 the alimentary canal. The hollow 

 ciliated tentacles surrounding the 

 mouth are concerned partly in 

 respiration, and partly in creating 

 currents in the water, and so 

 bringing food to the animal. The 

 intestine can be protruded from, 

 or retracted within the sac by Bowerbankia : 

 means of muscles. The intestine a, oesophagus ; b, giz- 

 is curved, so that the anus opens *f rd; ./- "ST* 



.. ' i_ XT i "> orifice of mtes- 



near the mouth. No heart or tine, 

 blood-vessels are present. The 

 fluid within the perivisceral cavity, which is sup- 

 posed to represent the blood, is clear and colour- 

 less, and is kept in continual motion by the cilia 

 lining the inner surface of the body-wall. The 

 nervous system consists of a single ganglion, 

 placed between the gullet and the anus. They 

 (Bryozoa) are all hermaphrodite, and reproduction 

 takes place by budding and by eggs. 



The Sea-mat (Flustra), so common on our 

 shores, is a well-known example. It is flat and 

 leaf-like in its form, and on the whole it presents 

 an appearance like brown sea-weed, for which it 

 is often mistaken. But, on examining its surface 

 carefully, it is seen to be studded over with little 

 openings, through which the little animals can. 

 protrude their tentacles. 



CLASS II. TUNICATA OR ASCIDOIDA. 



The Tunicata are defined as having the ' ali- 

 mentary canal suspended in a double-walled sac, 

 but not capable of protrusion and retraction. 

 Mouth opening into the base of a respiratory sac, 

 whose walls are more or less completely lined by 

 a network of blood-vessels.' 



They are all marine. Take one of the solitary 

 forms, Ascidia, as the type. It is globular in 

 form, and consists of a double-walled sac, the 

 outer layer of which contains cellulose, and is of a 

 tough leathery consistence. It is perforated by 

 two apertures placed close to each other, one the 

 oral, the other the anal opening, so that the whole 



