H. gammarus is the type species of the genus Homarus Weber , 1795 , as determined by Direction 51 of the International Commission on Zoological Nomenclature . Prior to that direction , confusion arose because the species had been referred to by several different names , including Astacus marinus Fabricius , 1775 and Homarus vulgaris H. Milne @-@ Edwards , 1837 , and also because Friedrich Weber 's description of the genus had been overlooked until rediscovered by Mary Rathbun , rendering any prior assignments of type species ( for Homarus H. Milne @-@ Edwards , 1837 ) invalid for Homarus Weber , 1795 .