670 MYRIOrODA. 



SUB-CLASS III. MYRIOPODA. 



The Mja'iopocls are readil}^ known by their long, cylindrical 

 or somewhat flattened bodies, which are composed of from ten 

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

 head is free from the rest of the bod}', and is nuich like that 

 of insects, while the thoracic rings are scarce!}^ distinguishable, 

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

 numerous abdominal rings, so tliat tlie head, instead of being 

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

 the thorax is merged in the abdomen. 



The head of Cermatia shows how closel}' the highest Myrio- 

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

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

 compound ej-es, the long filiform antennae, 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 Myriopods the mouth-parts are of the same 

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

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

 ocelli, and immediately behind them the antenna? ; behind 

 the mouth are the mandibles, the maxillae with their palj)i, and 

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

 sented by an elemental ring we have four segments in tlie 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 sj'stems very closely resemble those of the 

 larvae of insects, as does the external form of these animals. 



Newport states that the nervous system of Myriopods 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 



