What is the difference between insects and lancelet?

Insects have no internal skeleton. There is only an outdoor one. Its function is performed by a chitinized cuticle. The lancelet has a notochord that persists throughout life. In insects, the NS includes: the periopharyngeal ganglia and the abdominal nerve cord. In the lancelet, the nervous system is represented by a neural tube. Insect blood mixes with the body cavity and washes all organs. In the lancelet, it is closed. Insects breathe with tracheas, and in the lancelet, gas exchange occurs with the help of gill slits.