16 MEMOIRS NATIONAL ACADEMY OF SCIENCES. [voL.xn. 



Group 4. Lot 38. From McHenrys Ford to Bussels Ford, about 3 miles south of Shawanee, 

 Tenn. August 31, 1899. Rocky bottom. About 69 miles from lot 45, the headwater shells. 



This series is from the vicinity of Cumberland Gap, and is from about the same region where 

 the Powell River is thought by CampbeU ('94) to have turned northward and flowed through 

 Cumberland Gap as a tributary to the Cumberland River in Kentucky. Shells smooth, iater- 

 grading and spinose. 



Lot 37. Powell River Station, Tenn. On the Knoxville and Middlesboro branch of the 

 Southern Railroad, above Island Ford. August 30, 1899. Cf. Maynardville sheet, U. S. G. S. 

 These shells were taken from Bryant Shoals, above the mouth of Gap Creek, on downstream 

 to Powell Station. Gap Creek heads near Cumberland Gap. The proximity of these sheUs 

 to Cumberland Gap is also to be noted. Gap Creek does not contain these shells, as it is too small 

 a stream. 



The shells of lots 37 and 38 are shown in plate 31. The series does not appear homogeneous. 

 Their relations are doubtful. The shells which are at first smooth and become spinose are thus 

 related to lyttonensis. 



Group 5. Lot 29. Greens Ford, extreme southwestern corner of Claiborne County, Tenn. 

 The river bottom was rocky. August 23-24, 1899. About 34 miles from lot 38. Spinose 

 shells with a few of powellensis. 



Lot 28. Powell River P. O., Campbell County, Tenn. About 4^ miles below Greens Ford. 

 Rocky bottom. August 23, 1899. 



Lot 31. Craigs Ford, mouth of Cedar Creek, about 3^ miles above the mouth of Powell 

 River at Agec, Tenn. Gravel bottom. August 22, 1899. 



Lot 30. Mouth of Powell River, Agec, Tenn. August 22, 1899. The distance covered by 

 this group is about 15 miles, and the fall of the river is about 3 feet per mile for this distance. 

 From Big Stone Gap to the mouth of Powell River is 117 miles. 



The affinities of the shells of group 5 are similar to those of group 4, and are of similar uncer- 

 tain relationship. 



2. CLINCH RIVER. 



In southwestern Virginia, along the Norfolk & Western Railway, Clinch River drainage 

 is reached at Tip Top (Pocahontas sheet). But on accoimt of the small size of the stream it 

 was not examined untU Kelly or North Tazewell was reached (Tazewell sheet) . Here the stream 

 was found dammed, and I was told that it had been so for many years. No trace of lo could 

 be found, not even weathered shells, either below the dam or upstream above its influence. 

 At Cedar Bluff sand and gravel bars were carefully examined but with only negative results. 

 At Cleveland, Va., however, about a mile above the town, I foimd the first live specimens of 

 lo. Three dead shells were also foimd at Cleveland, lot 193. 



Group 6. Supl. lot 194. Finney Siding, Va. Below the mouth of Big Cedar Creek, on a 

 sandbar. August, 1899. Two fragments of shells, one smooth and the other with incipient 

 nodules. As these shells are worn, the living shells are probably still farther upstream. These 

 furnish the known upstream limit in the Clinch, 



Supl. lot 198. Cleveland, Va., and upstream to near the mouth of Big Cedar Creek. August 

 3, 1899. Thirteen specimens of dead shells were found along the river, clinchensis. 



Lot 56. Cleveland, Va. Found on a shoal, about 1 mfle upstream. Collected by J. L. 

 Litton from a bar near his home, about the middle of November, 1899. This is the series of shells 

 figured in part on plate 34. These are the form clinchensis. A good series. 



Supl. lot 193. Cleveland, Va. August 1, 1899. A series of four specimens, three of which 

 were dead, and the first five specimen taken. One of the dead shells is nodulose on most of 

 the body whorl. 



Supl. lots 197 and 217. Cleveland, Va, August, 1899. Two series of dead shells taken from 

 the river. These are of the same kind as the living ones. Such coHections of dead shells from 

 gravel bars show how reliable such collections are as samples of the local lo population. It 

 required hours of work to find the dead shells in this part of the river. 



