Arachnids are a major class of this phylum that includes insects & crustaceans
- Insects - About.com [PAR] The class Arachnida includes a diverse group of arthropods: spiders, ... to the 
phylum Arthropoda include: Insecta (insects), Crustacea (crabs), Chilopoda... [DOC] [TLE] Phylum Arthropoda - Biology Questions [PAR] Study insects, crustaceans, arachnids using intelligent questions and answers.