670 MYRIOPODA. 



SUB-CLASS III. MYRIOPODA. 



THE Myriopods are readily known by their long, cylindrical 

 or somewhat flattened bodies, which are composed of from ten 

 (counting the head as one) to over two hundred rings. The 

 head is free from the rest of the body, and is much like that 

 of insects, while the thoracic rings are scarcely distinguishable, 

 either in form or the character of their appendages, from the 

 numerous abdominal rings, so that the head, instead of being- 

 soldered to the thorax as in the spiders, is here free, while 

 the thorax is merged in the abdomen. 



The head of Cermatia shows how closely the highest Myrio- 

 pod agrees with the insects. The few (sixteen) segments 

 composing the body (counting the head as one) ; the large 

 compound eyes, the long filiform antenna?, and well developed 

 palpi, farther show the close relationship of this form to the 

 insects. The habits of this genus also remind us of the spi- 

 ders, as they are predaceous and are said to leap after their 

 prey. 



In the Chilopod Myriopocls the mouth-parts are of the same 

 number, and follow each other in the same order as in the 

 insects. Thus in advance of the mouth there are first the 

 ocelli, and immediately behind them the antennae ; behind 

 the month are the mandibles, the maxillee with their palpi, and 

 the labial palpi. As each of these jointed organs is repre- 

 sented by au elemental ring we have four segments in the head. 



In the embryo of Julus the rudiments of the first pair of 

 legs are soon aborted, and thus the first thoracic ring bears 

 no legs in adult life. The legs are composed of a coxa, a 

 femur, a tibia and a tarsus, as in the higher insects. 



As shown by Newport the nervous, digestive, respiratory 

 and reproductive systems very closely resemble those of the 

 larva! of insects, as does the external form of these animals. 



Newport states that the nervous system of Myriopocls ap- 

 proaches nearer, in the simplicity of its formation, to that of 

 the Annelids than that of the larvae of insects. "In the 

 Chilopoda it has the form of a double cord connected by large 



