species, female, male, males, adult, characters, individuals, closely, variety, latter, groups, distinctly, remarkable, conspicuous, British, occurrence, developed, Species, absent, chiefly, Natural, markings, showing, hairs, Greenland, recent, resemble, northern, mostly, offspring, aquatic, occurring, coloration, naturalists, related, Plate, variations, Linnaeus, egg, belongs, Australia, hatched, resembling, preceding, nomenclature, consists, naturalist, previously, reproductive