Varicose veins are large, raised, swollen blood vessels that twist and turn. They usually develop in the legs and can be seen through the skin. Spider veins are smaller, red, purple, and blue vessels that also twist and turn. Spider veins are easily visible through the skin, as well.
Common name: Flatworms. 1  Scientific name: many species. Phylum: Platyhelminthes. 2  Description: Although they are called Flatworms, these invertebrates are not flat. They are round-bodied with a flat belly. 3  Fun facts: A Flatworm has a single opening to its stomach, in the middle of its underside.
Tapeworms. A classic example of parasitic flatworm in humans is tapeworm (scientific name, Taenia species). Categorized under the taxonomic class Cestoda, tapeworms are also known as cestodes and the disease caused by these parasites is called cestodiasis.hese flatworms are capable of causing diseases in different host organisms, such as fish, dogs, domesticated animals, and humans. Advertisement. Flatworms are invertebrates, characterized by their minute-size or flattened, unsegmented, bilateral, soft body.