The following kinds of types are recognised by the Code. To avoid confusion no other terms should be used:
- Syntypes – where a description has been based on a series of specimens, these collectively constitute the name-bearing type (Article 72.2-72.4; 73.2).
- Lectotype – One of a number of syntypes which has been designated later as the single name-bearing type of a species, the remaining syntypes become paralectotypes and have no further name-bearing function (Article 74).
- Paralectotype – see lectotype.
- Holotype – A single specimen designated or otherwise fixed as the name bearing type of a species name when it was first described (Article 73).
- Paratype – Where there is a holotype, the other specimens in the type series are paratypes (Rec. 73D), and they have no name-bearing function.
- Hapantotype – A special kind of holotype in the case of extant protistans, which can consist of more than one individual (Article 73.3).
- Neotype – A single specimen designated as the name-bearing type of a species name when the original type(s) is lost or destroyed and a new type is needed to define the species. Under exceptional circumstances the Commission may use its plenary powers to designate neotypes for example if an existing name bearing type is not in accord with prevailing usage (Article 75).
- Allotype – a designated specimen of opposite sex to the holotype. This term has no name bearing function and is not regulated by the code (Rec. 72A).
Type of Case: