From Arkansas

St. Louis, July 5. Upwarda of 300 rebel prisoners arrived on the sUamer Gladiator, from Little Rock, yesterday in chartre of a battallion of 'Merrills' Horse Veterans, who are on a furlougti. They lult for Rock Island last night. Officers froin Duvul's Bluff, Ark., June 30th, say, Sheldon has not re turned to Olarendon, but it was thought fee would do so. Marmaduke is still outh of the Arkansas river 15 miles tbfilow Napoleon. His force eonsisted of hia own,and Bridge's, Dickey's, and Cabel's, about 6,000 tnen, wilh six or eight pieces of ilillery. There is no rebel artiüery betweeti the Arkansas And White Rivera, and only threecoin"pan'ies of guerrillas. The apprehension ■of a siega of LiUle Rock is miioh diininishei There is but one brigade of rebela Gn Saline River. The design of the rebote is evidently to cut of Steele's White Uwer commuuioations, which, 'boweTeT, wül bo very difficnlt, but il it ehould be done, Duvall's Bluft and Little Rouk have throe months' provisión.. White River is patrolled by tin clads, jsupported by a land f oree.