GEOGRAPHY OF THE REGION. 331 



neutralize these favorable conditions and occasion the presence of 

 vegetation which is decidedly desert-like. 



GEOGRAPHY AND PHYSIOGRAPHY. 

 GENERAL GEOGRAPHY OF THE REGION. 



The territory embraced in this report under the designation "Dis- 

 mal Swamp Region" lies, roughly, between parallels 30° and 37° N. 

 latitude and meridians 75 n 50' and 70° 35' W. longitude. It covers a 

 considerable part of the Coastal Plain ' area in southeastern Virginia 

 and northeastern North Carolina. It is bounded on the north by the 

 mouth of the James River (Hampton Roads) and of Chesapeake Bay, 

 on the east by the Atlantic Ocean, on the south by Albemarle Sound, 

 and on the west approximately by the western border of the Great 

 Dismal Swam]). The region, therefore, comprises the whole of 

 Princess Anne and Norfolk counties and the eastern portion of 

 Nansemond County in Virginia and the whole of Currituck, Camden, 

 Pasquotank, and Perquimans counties in North Carolina. 



Owing to the limited time which could be devoted to the survey, 

 not every part of the area thus defined was thoroughly explored. The 

 southern or North Carolina portion was only superficially ami par- 

 tially examined, the counties of Currituck and Camden having been 

 traversed merely by railway. On the other hand, a large part of 

 Princess Anne and Norfolk counties, Va., as well as of that section 

 of Nansemond County which lies within the borders of the Dismal 

 Swamp, was explored with considerable care. 



The greatest length of the region, from Willoughby Spit south to 

 Albemarle Sound, is nearly 96.5 kilometers (GO miles). Its greatest 

 width, along the Virginia-North Carolina boundary, is about 65 kilo- 

 meters (40 miles). Approximately the area embraces 6,200 square 

 kilometers (2,400 square miles). 2 The whole is a flat or slightly undu- 



'In order that the term "Coastal Plain." as here employed, may be [perfectly 

 clear to readers, I may be allowed to quote from Mr. N. H. Darton's manuscript 

 the following definition: 



■'The central and southern portions of the Atlantic slope of the United States 

 embrace four provinces of very distinct characteristics. From the westward there 

 is. first, the plateau province, which comprises broad basins, occupied by upper 

 Paleozoic rocks. The second is the Appalachian province, consisting of high, 

 longitudinal ridges, due in greater part to sharply folded middle and lower Pale- 

 ozoic rocks. Third, the Piedmont Plateau province, a region of undulating 

 plains, extending from the Blue Ridge with a gradual declivity eastward, and 

 underlain by crystalline rods. And, fourth, the Coastal Plain, a province bur- 

 dering the ocean, deeply invaded by tide- water estuaries and underlain by gently 

 east-dipping unconsolidated strata from early Cretaceous to Recent age." 



- This figure would be eonsiderahly smaller if we subtrat t the area of the numer- 

 ous salt-water bays and lagoons which extend inland, especially on the north and 

 east. 



