Nemertea is a phylum of animals also known as ribbon worms or proboscis worms, consisting of 1300 known species. Most ribbon worms are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies. Many have patterns of yellow, orange, red and green coloration. The foregut, stomach and intestine run a little below the midline of the body, the anus is at the tip of the tail, and the mouth is under the front. A little above the gut is the rhynchocoel, a cavity which mostly runs above the midline and ends a little short of the rear of the body. All species have a proboscis which lies in the rhynchocoel when inactive but everts to emerge just above the mouth to capture the animal's prey with venom. A highly extensible muscle in the back of the rhynchocoel pulls the proboscis in when an attack ends. A few species with stubby bodies filter feed and have suckers at the front and back ends, with which they attach to a host.
Orthonectida is a small phylum of poorly known parasites of marine invertebrates that are among the simplest of multi-cellular organisms. Members of this phylum are known as orthonectids.
A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species and also in some species of Ctenophores. Some groups of Nemerteans also produce larvae that are very similar to the planula, which are called planuliform larva.
Anopla has long been used as name for a class of marine worms of the phylum Nemertea, characterized by the absence of stylets on the proboscis, the mouth being below or behind the brain, and by having separate openings for the mouth and proboscis. The other long used class of Nemertea are the Enopla. Although Anopla is a paraphyletic grouping, it is used in almost all scientific classifications. Anopla is divided into two orders: Palaeonemertea and Heteronemertea.
Palaeonemertea is a class of primitive nemertean worm. It may be para- or polyphyletic, consisting of three to five clades and totalling about 100 species.
Terrestrial animals are animals that live predominantly or entirely on land, as compared with aquatic animals, which live predominantly or entirely in the water, and amphibians, which rely on a combination of aquatic and terrestrial habitats. Some groups of insects are terrestrial, such as ants, butterflies, earwigs, cockroaches, grasshoppers and many others, while other groups are partially aquatic, such as mosquitoes and dragonflies, which pass their larval stages in water. Terrestrial animals tend to be more developed and intelligent than aquatic animals.
Enopla is one of the classes of the worm phylum Nemertea, characterized by the presence of a peculiar armature of spines or plates in the proboscis.
A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. Land snail is the common name for terrestrial gastropod mollusks that have shells. However, it is not always easy to say which species are terrestrial, because some are more or less amphibious between land and fresh water, and others are relatively amphibious between land and salt water.
Geoplanidae is a family of flatworms known commonly as land planarians or land flatworms.
Parborlasia corrugatus is a proboscis worm in the family Cerebratulidae. This species of proboscis or ribbon worm can grow to 2 metres in length, and lives in marine environments down to 3,590 metres (11,780 ft). This scavenger and predator is widely distributed in cold southern oceans.
Lineidae is a family of nemertean worms. It contains the following genera:
Prostoma jenningsi is a species of ribbon worm known only from one site near Croston, Lancashire. It was described in 1971, and is believed to be the county's only endemic species. It grows up to 20 mm (0.8 in) long, with 4–6 black eyespots, and has a long eversible proboscis.
Prostoma is a genus of freshwater nemerteans, containing the following species:
Gononemertes australiensis is a parasitic ribbon worm. It lives commensally in the ascidian Pyura pachydermatina found in the sublittoral waters of the New Zealand. G. australiensis was found in specimens of P. pachydermatina collected in Sydney harbor. These worms were found specifically in the atrium of P. pachydermatina. It is dioecious and has several gonads. Each of its gonads produce several oocytes while the male worms carry testes along its parenchyma. Fertilization is external.
Malacobdellidae is a monogeneric family within the phylum Nemertea. It is included with the order Hoplonemertea within the class Enopla.
Bipaliinae is a subfamily of land planarians found mainly in Madagascar, the Indian subcontinent and Southeast Asia, although some species have been introduced worldwide.
Argonemertes is a genus of nemertean worms belonging to the family Prosorhochmidae. It may be transferred to the family Plectonemertidae. It contains the following species:
Bipalium vagum is a land planarian in the subfamily Bipaliinae. It has been accidentally introduced in the United States, Bermuda and various islands in the Caribbean and was recorded for the first time in Europe, in Italy, in 2021.
Notospermus is a genus of nemertine worms that includes marine species. Genus contains the following species:
Geonemertes is a genus of nemerteans belonging to the family Prosorhochmidae.
