CK-12 Foundation
Ck 12: Life Science: Segmented Worms
[Free Registration/Login may be required to access all resource tools.] When you think of worms, you probably picture earthworms. There are actually many types of worms, including flatworms, roundworms, and segmented worms. Earthworms...
Estrella Mountain Community College
Estrella Mountain Community College: Phylum Annelida
This section (in table of contents as "Phylum Annelida: Segmented Worms") gives a description of how segmented worms developed certain characteristics as well as it explains the differences in the evolution of different classes of...
CK-12 Foundation
Ck 12: Life Science: Roundworms
[Free Registration/Login may be required to access all resource tools.] The word "worm" is not very scientific. This informal term describes animals that have long bodies with no arms or legs. Worms with round, non-segmented bodies are...
CK-12 Foundation
Ck 12: Biology: Annelids
[Free Registration/Login may be required to access all resource tools.] Discusses characteristics of annelids like earthworms.