Since Parts I. & III. of my catalogue were published, Dr. Watson has carefully looked into the various specimens of A. petraea sent from Canada, and has referred most of them as above. It follows therefore that almost all references to A.petraea in Parts I. & III. must be considered cancelled. See A. humifusa.
(3076.) S. sinapistrum, Crantz.
S. Pannonicum, Jaeg.
This species has been introduced in a number of places along the line of the Canadian Pacific Railway. Castle Mountain, Rocky Mountains, 1885. (Macoun.) Near Nepigon Bridge, Lake Superior, 1886. (Fletcher.) At Port Arthur, Thunder Bay, Lake Superior, 1889. (Dr. Britton.) On an embankment along the C. P. Ry., about 300 yards west of Burketon station, 45 miles east of Toronto, 1889. (W. Scott.)