VARIOUS KINDS OF UNIO SHELLS 79 



shell for use as button material, but in some rivers these 

 are not so valuable on account of the great depth of 

 the ridges, which reduces their value as button material. 



Another variety which is almost like tlie "'three ridge" 

 is The Quadnda plicata, or "blue point." These two va- 

 rieties are so similar that some do not realize that there 

 is a difference between them. The "blue point" is a bet- 

 ter shell for use in the manufacture of buttons, as it is 

 flatter and does not have such heavy beaks. It is com- 

 mon in most places where the "three ridge" is found. 

 Both varieties yield pearls, yet the pearl hunters expect 

 more nice ones from the "blue points." 



The Lampsilis ligamentinus, or "mucket," or "mougat," 

 about one-third natural size, can be seen in Fig. 14. In 

 some rivers this shell is nearly equal to the "niggerhead" 

 for use in the making of buttons. It has the advantage 

 of being plentiful in most of our rivers. In some places 

 a few have to be discarded on account of their pink 

 nacre, but the shells are generally white. Being rather 

 flat, smooth, and of uniform thickness, this shell can be 

 worked up into button blanks without much waste. Prob- 

 ably more mnckets are used in the manufacture of but- 

 tons than any other variety. This variety is not often 

 found in lakes or small streams, but is the most common 

 variety in rivers. 



This species can be easily propagated. The glochidia 

 fasten themselves quickly to bass, perch and sunfishes. 

 It thrives well under many conditions and is better than 

 any other species for restocking rivers. 



