64 Laboratory Guide in Zoology 



THE FLATTENED CENTIPEDE, OR THOUSAND-LEGS 



The common " thousand-legs," or centipedes, are found 

 under boards and logs. For this study those with flattened 

 bodies should be selected. 



I. — Observe the jointed nature of the body. See that the 



head is easily distinguishable. Is there any distinct 

 division between thorax and abdomen ? From a dorsal 

 view, count the segments back of the head. Are all 

 the segments of the same size ? 



II. — Count the pairs of legs. Does each segment bear 

 one or two pairs .'' Study the legs carefully. Are 

 they jointed ? If so, how many segments has each ? 



III. — Find the breathing pores, or spiracles: one on each 

 side of a segment, just above the coxa, the first leg- 

 joint. 



IV. — Examine the antennae — the most noticeable append- 

 ages of the head. Directly behind the antennas find 

 the eyes — blackish clusters made up of many ocelli, 

 or single eyes, crowded near together. 



V. — Directly in front of the base of the antennae, find 



two pairs of mouth parts, or jaws, one pair being much 

 smaller than the other. But first distinguish carefully 

 the front pair of legs, so much modified that they look 

 like sharp claws. In poisonous species the poison is 

 secreted in these claws. 



VI. — Make a good-sized sketch of the centipede as seen 

 from the dorsal side, and another of the head as seen 

 from the ventral side. 



