New York, Julj 3. The U. S. steam reverme cutter llarrict Lane, Capt. Faunce, seized this afternoon, outside of Sandy Hook, the bark Kate, Captain Otto, on suspicion of about bcing engaging in the slave trade. ïhe Kato was cloared at the Custom Ilouse by Gapt. Watts, bound to Cape Palmas, west coast of África, and sailed to-day. Shc was brought back to the city and anchored off the battcry. Uerercw is composed prineipally of PortuguésO aad Spanïards, früm whom no mfnrtnation could be gained. Her cargo is such as slavers genorally carry. At tho time she was seizod Capt. Faunce observed some curious ïnovements of a steam tug, then some diötanoe off, and it seeming suspicious, ran tbr lier, whon it proved to be the Magnolia, having on board a number of men, of whom no reliable aeeount was given. Capt. F. having no doubt but that they were to be put on board the Kate, as appearances indicated, imtnediately seized tho tug and brought her here, and detained her passongers for examination.