ANTHOCEROS, or HORN-FLOWER, a genus of the order of algae, belonging to the cryptogamia class of plants. The calix of the male is sessile, cylindrical, and entire; the antheræ are very long, subulated, and two-valved; the calix of the female is divided into six pieces; the seeds are three. There are only three species of the anthoceros, viz. the punctatus or spotted anthoceros, a native of Britain; the laevis, a native of Europe and America; and the multifidus, a native of Germany. It is found in moist shady places, and on heaths.