The New Dictionary of Cultural Literacy, Third Edition. 2002.
species
(SPEE-sheez, SPEE-seez) A group of closely related and interbreeding living things; the smallest standard unit of biological classification. Species can be divided into varieties, races, breeds, or subspecies. Red pines, sugar maples, cats, dogs, chimpanzees, and people are species; Siamese cats and beagles are varieties, not species. (SeeLinnean classification.)