homeothermic vs. homoiothermic
heterothermic vs. poikilothermic
haematopoietic vs. hematopoietic
haemopoietic vs. hematopoietic
haematogenic vs. hematopoietic
hieroglyphic vs. hieroglyphical
hydrographic vs. hydrographical
hypoglycaemic vs. hypoglycemic
haematological vs. hematologic
hypophysectomised vs. hypophysectomized