with whom Mr. Justice Powell joins, concurring.
Although there are many indications in the District Court’s opinion that it not only considered Tucker v. Salera, 424 U. S. 959 (1976), controlling, but also independently invalidated the Maryland law on grounds similar to or the same as those employed in Salera — in which event, a remand would be inappropriate — -it is fairly arguable that the District Court should unmistakably record its opinion as to the validity of the Maryland law. A number of my Brethren are of this view, and I defer to their judgment.