Phylum Nemathelminthes: It is a phylum of unsegmented triploblastic pseudocoelomic cylindrical or thread-like worms which are covered by a body wall having cuticle and epidermis. Phylum Nemathelminthes includes roundworms and threadworms. It includes more than 15,000 species. This group was established by Grobben in 1910. Characteristics of Phylum Nemathelminthes: Most of the animals of nemathelminthes