The capture of an adult eastern soft-shell turtle,Trionyx ferox spinifera (LeSueur), in brackish water of a branch of West River, a tributary of Chesapeake Bay, Anne Arundel County, Maryland, is regarded as an example of introduction by man from an out-of-state source. It has been doubtfully recorded from the Susquehanna River above the Maryland line. It may have occurred naturally in the Youghiogheny River in the Ohio drainage system in extreme western Maryland, but mine waste pollution may have exterminated it. Although introduced in the Potomac River at Cumberland, Maryland, from West Virginia over 75 years ago, the stocking was apparently unsuccessful. Except for the present record, there is no authoritative evidence that it is now present in Maryland.