CARROLTON, a distance of six miles by the rail-road, is an exceedingly pleasant resort. The line, for nearly a third of the way, passes through the suburbs of the city, and is dotted on either side with beautiful residences--the remainder passes through cultivated fields, pleasant pastures, and delightful wood-lands. The road, like the country, is perfectly level, and kept in the finest condition. At the end of the route is situated the village; which is principally composed of tastefully built cottages, constructed in every variety of architecture that suited the individual fancy of the owner. Opposite the rail-road depôt, is one of the handsomest and most extensive public gardens, that is to be found in the vicinity of New Orleans. A race course is near by; and the strolls around are quite cheering to those who fly from the turmoil and dust of the metropolis. THE SHELL ROAD of the Canal and Banking Company, affords an agreeable ride to lake Pontchartrain, also a distance of six miles. The highway runs on the margin of the canal, and is not excelled by any road in the United States. It is the great resort for every species of pleasure vehicle that the city furnishes; and here may be seen, on an afternoon, all grades of society, from the gay sportsman, mounted on his fast trotter, to the sober citizen, who sallies forth on his ambling poney, all of whom appear to realize an equal share of enjoyment. A line of comfortably arranged barges also ply on the canal from the lake, at which place a convenient hotel is established. Half way on this road, between the city and the lake, is the highly celebrated Metairie race track. THE PONTCHARTRAIN RAIL-ROAD, runs to the lake from which it derives its name, from the head of Elysian Fields street, a distance of five miles. It is a very pretty ride. This route communicates with the great northern mail line, which goes by the way of Mobile--and all the steamboats, that traverse the lakes to the various villages and landings that surround it, make this their general starting point. From here, a passage is obtained to Biloxi, which, the reader will recollect, was the first spot settled by the French in this portion of the world; and, from that circumstance, will naturally excite the curiosity of the intelligent wayfarer. At the termination of this rail-road is a first-rate hotel for the accommodation of visitors. Here is good bathing, fishing and shooting; and, beneath the shade of the trees, the breeze from the water is delightfully refreshing.