MyRIAPODA. 799 



two parts. Except the back, the whole body and the feet are covered with 

 long bushy hair. The extremities of the feet are smooth and large, like the 

 toes of a dog. 



This hideous species of the spider tribe preys principally on small birds ; 

 in doing of which, it tears them to pieces to get at their blood, and after- 

 wards sucks their eggs. 



CLASS VIII.— M YRIAPODA. 



Head distinct, with two antenncB ; mandibles simple, incisive ; feet on all or most 

 of the segments of the body. 



The animals of this class were arranged among the apterous insects by 

 Linnaeus, under the generic appellations of Scolopendra and Julus. Fabricius 

 placed them as a division of his class Arachnides ; and Dr Leach, in the 

 Edinburgh Encyclopedia, fixed their characters as a distinct class, in which 

 he has been followed by Latreille and the later writers. 



The Myriapoda, allied to the two preceding classes in their general 

 structure, approach the insects in the organization of their respiratory appa- 

 ratus. This consists of two principal trachea or air tubes, extending longi- 

 tudinally and parallel to one another, the whole length of the body, which 

 receive the air by numerous lateral spiracles. Their sexual organs are also, 

 as in these, single. The feet, indefinite in number, but always more than 

 six, are inserted by single or double pairs on the segments of the body, and 

 increase in number as the body is elongated from age. From their great 

 number of feet, the animals of this class have been designated by the term 

 Millepedes. The Myriapoda, in general, have the form of small serpents or 

 worms, with an elongated body of numerous segments, and of the same 

 thickness, and crowded with feet along its whole length. Their head is fur- 

 nished with two short antennae, composed of seven joints. They have two 

 granulated eyes, formed by the junction of numerous and smaller smooth 

 ones ; two dentated mandibles, proper for bruising or cutting their food, and 

 divided transversely by a suture ; and a labium or lip without palpi, formed 

 of united portions. The two or four anterior feet, joined at their base, are 

 analogous to the pedipalpi of the Crustacea. The stigmata or air vessels 

 are often very small, and exceed in number those of insects. The nervous 

 system in the Myriapoda is composed of a series of ganglia, one in each 

 segment of the body, communicating bv a longitudinal chord. The animals 

 of this class are found under stones, the bark of trees, &c., and feed on 



