MUSSELS OF CUMBEKLAND EIVER AND TRIBUTAEIES. 29 



Lampsilis fallaciosa, the slough sand-sliell, which were tho first 

 obtained during our survey of the river. 



At Brimstone Island there is a large mussel bed in water from 2 to 

 8 feet deep, with a bottom of coarse gravel, sand, and clay. Com- 

 mercial clamming had been in operation here only a few days before 

 our arrival, but must have been carried on during previous years, as 

 evidenced by a pile of button shells on the bank containing fully 

 20 tons. 



At Carsons Bar there is another large mussel bed in water from 3 

 to 6 feet deep, with a moderate current and a hard gravel bottom. 

 This bed is worked only occasionally by local fishermen chiefly for 

 fish bait and pearls. 



Roaring River, a tributary from the south which enters the Cum- 

 berland just above Gainesboro Landing, was examined several miles 

 above its mouth on July 28. Only one small mussel bod was found 

 along the shore under the shade of the overhanging trees, in 3 to 6 

 inches of water on a gravelly bottom. The presence of a large amount 

 of Potomogeton and the abundance of Medionidus conradicus was a 

 strong reminder of the Rock Castle River at Livingston, Ivy. The 

 abundance of Lampsilis glans was also noteworthy, since this species 

 was not found anywhere in the main river. 



At Gainesboro Bar there is a small mussel bed which can not be 

 worked with a crowfoot dredge, since the bottom is composed of flat 

 roclvs with gravel pockets in the cracks. At the lower end of the bed, 

 where the rocks were well covered with a blue clay, the mussels were 

 of especially fuie quality, but the bed has never been fished com- 

 mercially. 



We reached Salt Lick Island when the water was low and the 

 mussels were moving about actively. Similar conditions were found 

 at Half Pone Bar (see p. 33), and the extremely interesting collections 

 obtained at each of these stations show what a remarkable difference 

 a low stage of water makes in the results of collecting. There is no 

 reason for supposing these two beds to be exceptionally good, and 

 probably most of the beds in the Cumberland would have nearly if 

 not quite equaled them if the conditions under which they were 

 examined had been equally favorable. This Salt Lick Island bed 

 was especially noteworthy for the large numbers of TrunciUa that 

 were obtained. No parasites were found on any of the mussels. 

 Lampsilis gracilis was gravid (July 31), while L. llgamentina gihha 

 and L. orhiculata approached each other so closely in all their shell 

 characters as to be indistinguishable except by the color of the nacre 

 and epidermis. 



At Fort Blount Bar there is a large mussel bed in water from 4 to 

 6 feet deep, with a swift current over a bottom of firm gravel mixed 

 with yellow clay and sand. Two men from the Ohio River had been 



