...rilla McCown and three of his men were captured by the Forrester New York cavalry regiment, reconnoitring in the direction of Sperryville, Va.--A fight took place in Mobile Bay, between the rebels in Fort Morgan and the National gunboats stationed on the blockade. On the discovery, this morning, of a steamer ashore under the guns of the Fort, all the gunboats of the fleet got under way; and, while some rep...