SYSTEMATIC REVISION OF SPECIES. 



35 



SYSTEMATIC REVISION OF THE EQUIDzE WITH TYPE FIGURES OF THE SPECIES. 



Type Terms in Vertebrate Paleontology as Employed by the Author in this Memoir. 



Type terms and usage in vertebrate palaeontology acquire a somewhat different significance than in invertebrate 

 palaeontology (Schuchert) or in zoology (Allen). 



In this memoir the type specimen first mentioned by the author is regarded as the holotypc or lectotype. 

 Genotype. — The type specimen of the genus and species. 



Type (including Holotypc and Lectotype). — The actual individual specimens mentioned by the author in his type 

 description, equivalent to holotype in the strict modern usage. Holotypc is used where the species is founded on one speci- 

 men primarily, others, if any, being paratypes. A lectotype may be subsequently selected out of a series of cotypes or 

 paratypes (sensu strictu), and in this Memoir is always the first mentioned specimen. 



Cotype (including paratypc). — The second and subsequent specimens belonging to other individuals mentioned by the 

 author in his type description; in palaeontology equivalent to jwratype in the more strict modern usage of terms. 



Paratypc. — Specimen or specimens placed by the author with the type, of supposedly equal value and amplifying the 

 characters of the species. 



Neotype. — The specimen chosen in a subsequent paper by the original or another author as referable to the same 

 species and amplifying the characters of the type by affording fuller material for description. 



Topjotypjc. — A specimen subsequently found and described from the same locality and geologic level as the type. 



