In the Potomac Flotilla is the schooner Chotank. The G. W. Blunt and the Hope are in the South Atlantic Squadron; the Dart and Sam Houston in the West Gulf Squadron, while the Sam Rotan, Wanderer, and Beauregard (the last named captured from the rebels) are in the East Gulf Squadron. YACHTS--2 America: South Atlantic Squadron. Corypheus: West Gulf Squadron. These vessels are used chiefly as tenders and despatch vessels. MORTAR SCHOONERS--18. Arletta 3 guns, 199 tons. Adolf Hugel 3 " 269 " C. P. Williams 3 " 210 " Dan Smith 3 " 149 " Geo. Mangham 3 " 274 " Henry Janes 3 " 261 " John Griffith 3 " 246 " M. Vassar 3 " 182 " Maria A. Wood 2 " 344 " Norfolk Packet 3 " 349 " Orvetta 3 " 171 " Para 3 " 190 " Racer 3 " 252 " Rachel Seman 2 " 303 " Sophronia 3 " 217 " Sarah Bruen 3 " 233 " T. A. Ward 3 " 284 " Wm. Bacon 3 " 183 " Of these eighteen mortar schooners, five are at Baltimore, two in the North Atlantic Squadron, five in the West Gulf Squadron, one in the East Gulf Squadron, four in the Potomac Flotilla, and one in the James River Flotilla. We have thus given the statistics of the sailing vessels of the navy. We now give a table of the steam vessels of all descriptions in our navy, which are the most valuable auxiliaries we have. It is probably the most effective steam navy in the world, and in its department of huge iron-clads cannot be excelled even by the navies of the old world. The steam vessels of our navy may thus be enumerated: STEAM FRIGATES--9. Colorado 48 guns, 3,435 tons. Niagara 34 " 4,582 " Powhatan 11 " 2,415 " Minnesota 48 " 3,307 " Mississippi[4] 12 " 1,692 " Princeton 8 " 900 " San Jacinto 12 " 1,446 " Saranac 9 " 1,446 " Susquehanna 17 " 2,450 " The Niagara, one of the finest screw frigates in the navy, and which, with the Colorado, is now repairing, is noted for being connected with the Atlantic cable expedition, as well as for conveying the Japanese embassy home. She is the pet of the navy, and great credit is due the late George Steers for such a splendid specimen of naval architecture. The Powhattan, Minnesota, and Mississippi are attached to the South Atlantic Squadron; the San Jacinto to the East Gulf Squadron; the Susquehanna to the West Gulf Squadron, and the Saranac to the Pacific Squadron. The old Princeton is the receiving ship at Philadelphia. Of these steam frigates, six are screw, and three sidewheel. STEAM SLOOPS--10.