Nemertea analyses by molecular phylogeny are confident that members of Lophotrochozoa are more closely related to each other than of non-members, the relationships between members are mostly unclear. Most protostome phyla outside the Lophotrochozoa are members of Ecdysozoa ("animals that molt"), which include Arthropoda, Nematoda and Priapulida. Most other bilaterian phyla are in the Deuterostomia, which include Echinodermata and Chordata. The Acoelomorpha, which are neither protostomes nor deuterostomes, are regarded as basal bilaterians. Nemertea Nemertea is a phylum of invertebrate animals also known as "ribbon worms" or "proboscis worms". Alternative names for the phylum have included Nemertini, Nemertinea and Rhynchocoela. Although
Subgroups of cyclic groups cyclic, and that has a distributive lattice of subgroups, but that is not itself cyclic. Subgroups of cyclic groups In abstract algebra, every subgroup of a cyclic group is cyclic. Moreover, for a finite cyclic group of order "n", every subgroup's order is a divisor of "n", and there is exactly one subgroup for each divisor. This result has been called the fundamental theorem of cyclic groups. For every finite group "G" of order "n", the following statements are equivalent: This statement is known by various names such as characterization by subgroups. (See also cyclic group for some characterization.) There