In the female, they form an egg-laying structure called an ovipositor. As a part of your dissection, as you did for the crayfish, remove the appendages of the head and thorax from one side of the body. There are two of them, both of a female and both showing the same structures. The structures will correlate well with those you observe in the dissection. A slide showing a spiracle and attached tracheae of an insect.
Centipedes are one of the two myriapod groups.
Know the class characteristics. Millipedes are the other myriapod group. Know the class characteristics. The fundamental difference between the two is the degree of difference in morphology between larva and adult. Know its genus and phylum names as well as the features it shares with annelids and arthropods.