MUSSELS OF CUMBERLAND RIVER AND TRIBUTARIES. 



39 



many cases the epidermis alone left. That the mussels do not thrive 

 well in this portion of the river is probably due to the fact that the 

 bottom is rocky, food scanty, and the water deficient in lime. 



Below the Cumberland Falls in the limestone formations the water 

 contains a considerable percentage of lime. Here the shells are much 

 larger and thicker than those above the falls. 



The table given below is taken from the United States Geological 

 Survey ^^Water-Supply Paper 236," by R. B. Dole, and shows the 

 mineral conditions of the Cumberland River, at Nashville, Tenn., and 

 Kuttawa, Ky., two mdely separated localities of the lower river. A 

 sample of water was taken daily, these m.ixed, and a sample from the 

 mixture was taken for analysis. There were about 3 analyses made 

 per month, or 36 per year. This method gives a much better general 

 knowledge of the conditions than a single sample would do. From 

 Nashville the samples were collected from October 24, 1906, to 

 November 3, 1907, and 35 analyses made; from Kuttawa, from Jan- 

 uary 11, 1907, to January 11, 1908, 34 analyses were made. 



The following table gives the general average of the analysis, in 

 parts per million, and also the per cent of the anhydrous residue: 



Mineral Analyses of Water from Cumberland River. 

 [Parts per million, unless otherwise stated.] 



Anhy- 

 drous 

 residue. 



Near Kuttawa, 

 Ky. 



Anhy- 

 drous 

 residue. 



Turbidity 



Suspended matter 



Coefficient of fineness 



Silica (Si02> 



Iron (Fe)o 



Calcium (Ca) 



Magnesium (Mg) 



Sodium and potassium (Na-fK). 



Carbonate radicle (CO3) 



Bicarbonate radicle (HCO3) 



Sulphate radicle (SO4) 



Nitrate radicle (NO3) 



Chlorine (CI) 



Total dissolved solids 



3.6 

 9.6 

 0 



21.3 

 2.9 

 7.8 



22.8 

 3.5 

 6.3 



40.6 



COMMERCIAL VALUE OF THE MUSSELS. 



Taking into consideration both the relative abundance of the species 

 and the intrinsic value of the shell, the southern mucket {L. ligamen- 

 tina gihha) is the most important commercial mussel of the upper 

 river; that is, from Burnside down nearly to Nashville. 



