FRKSH-WATER MUSSEI.S AND MUSSEIv INDUSTRIES. 31 



Often the forward or butt part of the shell is somewhat chalky and comprises 

 scarcely more than one-fourth of the shell surface, while the remaining three-fourths 

 is too thin and brittle. A noteworthy feature of the shell is the lateral hinge, which 

 has a beautiful pearly luster. The cardinal teeth, too, have an attractive form and 

 are used in the manufacture of cheap jewelry. 



Lampsilis ovata (Say) (PI. XVII), the southern pocketbook or grandma, is not 

 ordinarily distinguished from ventricosa. It is found in the Ohio River and tributaries, 

 as in the Clinch, Holston, and Cumberland Rivers. It is rather thinner and inferior to 

 the common northern pocketbook. 



Lampsilis (Proptera) capax (Green) (PI. XVII), also called pocketbook and confused 

 with the others, is not closely related to them in spite of its superficial resemblance. 

 It is quite too thin for value in button manufacture. The purply Lampsilis (Proptera) 

 purpurata (Lamarck) (Pi. XVIII) is probably related to capax. It is very familiar to 

 shellers in Texas, Louisiana and Arkansas, but the thinness of the shell, as well as the 

 deep purple nacre, makes it unfit for the trade. It is one of the most beautiful shells. 



Another species which looks something like a young pocketbook, but which never 

 attains so large a size, is Lampsilis multiradiata (Lea) (PI. XVIII) of the Ohio drainage 

 and southern Michigan. Its shining greenish-yellow, bright-rayed shell is very attrac- 

 tive to the eye. 



SAND-SHElvI/ GROUP. 



There are three sand-shells, the yellow, the slough, and the black. 



The yellow sand-shell, Lampsilis anodontoides (Lea) (Pis. I, XVI and XIX), is the 

 most highly prized of all commercial shells. It is never very abundant, but it is probably 

 the most widely distributed of all the species discussed. Its distribution as given by 

 Simpson is: "Entire Mississippi drainage, except, probably, the upper Missouri. All the 

 Gulf drainage from the Withlacoochee River, Fla., to the Rio Grande, and into Mexico." 

 The common name is derived from the clear yellow or brownish-yellow exterior color. 



These shells are too valuable for use in button manufacture ; consequently they are 

 always sorted out. Many tons of them are bought from the fishermen on the rivers to 

 be used for export. Even those that reach the factories in mixed cars are sorted out in 

 the yard to be sold again to shell jobbers. In very recent years, however, due to war 

 conditions, many sand-shells have been cut into buttons in domestic manufacture. 

 Some years ago it was said that the sand-shells were shipped chiefly to Eirance; in the 

 few years preceding 1914 the greater part seemed to have been destined for the German 

 market, and the price on the rivers in 191 3 was $60 per ton. The export was neces- 

 sarily interrupted in 1914, but in the early part of 191 1 the writer was informed of an 

 offer of $92.50 per ton f. o. b. New York, and a consular report from Hamburg quoted 

 these shells at prices equivalent to from $108 to $151 per long ton, when niggerheads 

 were quoted in the same market at $54, and muckets at from $47 to $119. About 

 three pairs of sand-shells (the shells from three mussels) usually make a pound, so 

 that the mussels were worth at least i cent apiece on the river and, at the date of the 

 consular report, 2 cents apiece or more in Hamburg. In 1919, with some export 

 demand, yellow sand-shells bring about $90 per ton. 



The shell owes its value to the following characteristics: (i) Its luster and pearly 

 qualities are almost if not quite equal to the marine shells; (2) its texture is smooth and 



