Several fronds are usually seen growing from a root-stock, those produced early in the season commonly sterile, and shorter than the others. The full-grown and fertile fronds are often two feet or two and a half feet long, and about one foot broad. The general outline is oblong-ovate, the lowest pinnæ being scarcely, if at all, shorter than those in the middle of the frond. There are usually about eight or ten full-sized pinnæ each side of the rachis, besides the gradually diminishing pinnæ near the acute pinnatifid apex. The larger pinnæ are from five to eight inches long, the middle ones an inch or an inch and a half wide, but the lowest ones two inches and a half broad. The greatest breadth of the pinnæ is usually near the middle or even a little above the middle, so that they are slightly narrowed towards the base; and in this character lies one of the readiest distinctions between this fern and those large forms of _A. cristatum_, which have occasionally been mistaken for _A. Goldianum_; for in that other species the greatest breadth of the pinnæ is uniformly at the base. The segments of the pinnæ are from fifteen to twenty each side the midrib: the incisions do not extend quite to the midrib, so that the latter is narrowly winged, and the pinnæ are pinnatifid rather than pinnate. The segments are from nine to eighteen lines long, and about three lines wide: they are set rather obliquely on the midrib, and are often slightly curved upwards, or falcate. They are obtuse or somewhat acute, and have the edges crenate, or more or less distinctly serrate with sharp incurved teeth. The veins are free, and are pinnately forked into from three to five slender oblique veinlets, of which the lowest one on the upper side is the longest, and bears a fruit-dot near its base. The fruit-dots are seldom or never found on the two or three lowest pinnæ, but on the rest they are arranged in a row each side the midveins of the segments, and much nearer the midveins than the margins. There are in all from ten to twenty to a segment. The indusia are larger than in most of the related species, flat, perfectly smooth, orbicular with a very narrow sinus, and slightly erose-crenulate on the margin. In the second edition of Gray’s Manual it is said that the indusium is “often orbicular without a distinct sinus, as in _Polystichum_;” and it is sometimes difficult to see the sinus, but I think it is rather because the sides of it overlap than because there is none. The sporangia have a ring of from fifteen to twenty articulations. The spores are ovoid, and somewhat roughened on the surface.