40 



The following illustration, Figure 11, will convey to the reader a sufficient idea of the 

 arrangement of the internal organs of a spider, without any more detailed description. 



Figure 11. 



Section of a spider to show the arrangement of the internal organs ; a, b, upper and under 

 lips of the mouth ; c, c, the oesophagus ; e/, J\ upper and under muscles of the sucking stomach ; 

 e. stomach ; g, g, ligaments attached to diaphragm under the stomach ; £ lower nervous gang- 

 lion ; k, upper ganglion ; I Z, nerves to the legs and palpi ; m, branches of the stomach ; n, 

 poison gland ; o, intestine ; p, heart ; B, air-sac ; S, ovary ; t, air-tube ; it, spinning-glands. 



3. — Classification. 



To enter into a minute account of ,the classification of the Arachnida would be 

 very tedious, and occupy an undue amount of space. We shall therefore content our- 

 selves with mentioning some of the more important families of spiders, and describe 

 some of their characteristics. 



The largest known spiders belong co the family Mygalidce. They may be at once 

 distinguished by the shape of their mandibles and the terrible claws which proceed from 

 them. In most spiders the claws are set sideways (as in Epeira Figure 7, D.), but in this 

 family they are bent downwards, and strike the prey as a lion would clutch his victim 



with his curved talons. The body 

 is usually very hairy and dark-col- 

 oured. Most species have only four 

 spinnerets, one pair of which are 

 long and are turned up behind the 

 abdomen ; they have four air-sacs 

 under the front of the abdomen, 

 instead of two, as other spiders. The 

 eyes are collected together on the 

 front of the head. They live only 

 in warm countries. Figure 12 re- 

 presents My gale Hentzii, a species 

 found in Texas and Arizona. Many 

 wonderful stories have been told 

 about the ferocity of these huge 

 spiders, their power of catching and 

 eating small birds and other ani- 

 mals. These accounts were gener- 

 ally discredited and looked upon as 

 mere " travellers' tales," but of late 

 years fresh evidence has been pro- 

 duced by naturalists in proof of the 

 former stories. The following de 

 scription by Mr. H. W. Bates in his 

 interesting work, "The Naturalist 

 on the River Amazon, " (page S3), 

 sets forth the truth regarding thase 

 monsters : — 



4 Fig. 12 



