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CHARACTERS OF INVERTEBRATE ANIMALS 



Myriapods are divided into the following five orders : — 



1. Millipedes (Chilognatha or Diplopoda). 



2. Centipedes (Syngnatha or Chilopoda). 



3. Spider-legged Myriapods (Schizotarsia). 



4. Insect-like Myriapods (Symphyla). 



5. Larva-like Myriapods (Pauropoda). 



Order i.— MILLIPEDES (Chilognatha or Diplopoda) 



Millipedes (fig. 245) are vegetarian Myriapods, devoid of 

 poison-claws, and with cylindrical bodies. The legs are com- 

 paratively weak, and throughout the greater part of the trunk two 



pairs of them are borne by 

 each segment, their bases 

 being close together instead 

 of wide apart, as in a Centi- 

 pede. The antennae are 

 short and club-shaped, while 

 each of them is made up of 

 seven somewhat bell-shaped 

 joints. The mouth is pro- 

 vided with a plate -shaped 

 upper lip, strong mandibles, 

 and two pairs of maxillae 

 fused together into a broad 

 plate. There are two pairs of stigmata on each trunk-segment, 

 and also two small pores {^foramina repugnatoria), which are the 

 openings of defensive stink-glands. The eyes resemble those of 

 a Centipede in structure and position. 



Millipedes differ very much in length. A common British 

 species of average length is the Earth Snake-Millipede {lulus 

 terrestris), a sluggish creature about an inch in length, commonly 

 found under loose bark, &c., and with the habit of curling itself up 

 when alarmed. The Pill- Millipedes are short forms which roll 

 themselves into compact balls under similar circumstances. The 

 genus Glomeris is represented by British species. 



Fig. 245. — British Millipedes 



I, London Snake-Millipede {lulus Londinensis) ; 2, 3, Spotted 

 Snake-Millipede {lulus ^ttatiis], natural size and enlarged; 4, 5, 

 Earth Snake-Millipede {Ijilus terrestris) and antennas of same, both 

 enlarged : 6, 7, Flattened Millipede {Polydesmus coin^lariaius), 

 natural size and enlarged. 



Order 2. — CENTIPEDES (Syngnatha or Chilopoda) 



Centipedes conform in the main to the description already 

 given of the common British form {Lithobius). The large Centi- 



