Anatomy of Cnidarians Montessori Info Booklet! This learning resource contains an informational booklet for the parts of a cnidarian (sea anemone). Internal organs included in this booklet: cnidarian, body, mouth, tentacles, and nematocysts. If you would like to expand on this topic, check out my my other Montessori anatomy and zoology resources. You can also check out my set of internal anatomy of vertebrates.