50 ' MUSSELS OF CUMBEKLAND KIVEE AND TEIBUTAEIES. 



This species bears a general resemblance to an elongate flattish L. ligamentina. 

 Unstained shells are easily recognized by tlie character of the rays, which are broken 

 up and more strongly marked in places, making a series of heavy green blotches. 

 Another peculiarity is the short lateral teeth, 1 in the right valve and 2 in the left; 

 these are low and blunt, and separated from the cardinals by a wide interspace. 

 Our older shells are badly eroded and so stained and discolored that the character- 

 istic rays and blotches are absent. Such specimens can be recognized by the narrow 

 border of latest formed nacre, which is yellowish or reddish and semitranslucent. 

 Our shells usually have the nacre badly stained. Even if obtained free from staina 

 they would make rather poor button shells, as they are somewhat brittle. In thick- 

 ness they are about equal to a thin mucket. A few of the examples have brick-red 

 pimply patches on the interior which probably indicate the presence of parasitic 

 trematodes. No parasites, however, were noted. 



18. Lampsilis anodontoides (Lea). Yellow sand-shell. 



Rather uncommon, distributed chiefly through the central portion of the river, 

 and never forming a large percentage of any of the beds. This species thi-ives best 

 on sand bars in rather shallow water. It is generally confined to large streams. It 

 is one of the most active of the mussels, responding quickly to changes in environment 

 by moving about. This is by far the most valuable of the fresh-water mussels, the 

 shells being generally used for export and in the manufactm'e of knife handles. 



This species is easily propagated, the glochidia fastening readily to most of the 

 common spiny-rayed fishes, such as sunfishes, bass, etc. On June 13 we found a 

 number of gravid shells at Meeks Bar. Some sunfishes were caught, a tub was pro- 

 cured, and an infection made. The infected fishes were then liberated into the Cum- 

 berland in front of the blank factory at Clarksville. 



19. Lampsilis fallaciosa (Smith). Slough sand -shell. 



Rare in the Cumberland and not found in any of the tributaries. This species 

 thrives best along shore in shallow water with a rather lively cuiTent and muddy 

 bottom. Such conditions exist only in the very lowest portion of the Cumberland. 

 From Kuttawa to the Ohio side sloughs are more common and the species ia probably 

 more abundant. The nacre of most specimens secured is stained. This is a first- 

 class species for the manufacture of buttons, but it would be unprofitable to plant in 

 the Cumberland because of the absence of favorable locations for its best development. 



20. Lampsilis recta (Lamarck). Black sand-shell. 



Rather common tlu'oughout the entire length of the river, but nowhere abundant. 

 Many of the shells are badly eroded and stained; none are deep pink tliroughout, 

 but are pale pink about the cardinal teeth and in the umbonal cavity. 



Good white-nacred shells of this species are exceptionally excellent button shells, 

 and where select stock could be obtained would be one of the most desirable species 

 to propagate. 



2L Lampsilis lienosa (Conrad). 



The specimens we have are hardly tj^ical and were with some doubt identified as 

 this species. It is a small species of no commercial importance. 



22. Lampsilis vanuxamensis (Lea). 



The females of this species were gravid June G. They are peculiar in having the 

 marsupial expansion of the shell rather limited in area, not extending to the posterior 

 end, but followed by a pointed extremity. In this localization of the shell they 

 remind one somewhat of the Truncillas. The shells are small, red nacred, and of 

 no value. 



23. Lampsilis trahalis (Conrad). 



Found only in the upper part of the river and its tributaries. The females are not 

 markedly swollen posteriorly, but differ from the males in being shorter and broader. 



