180 UTILIZATION OF MINUTE LIFE. 



specimens are indeed sold in considerable numbers 

 attached to crucifixes made to hang against the wall. 

 This shell is also sought for to manufacture knife- 

 handles, penholders, and a number of elegant orna- 

 ments of various descriptions. 



To the same group belong the shells of the genus 

 Chama, which attain also a considerable size. These 

 and the shells of the Gasteropoda, Strombus and 

 Cassis, mentioned before, are those with which 

 cameos are made. 



Real or stone cameos are cut at great expense 

 in certain varieties of onyx, agate, or jasper. The 

 art of cutting these hard stones is very ancient, and 

 the ornaments thus produced realize a very high 

 price, especially when the workmanship is of a 

 superior quality. They are still cut in Italy, princi- 

 pally at Rome; but cameo artists are not unfre- 

 quently met with in other parts of Europe. 



The practice of working cameos on shells, and 

 producing what is called a shell cameo, has been in- 

 troduced at a comparatively modern period into 

 Italy. It is carried on to a great extent at Rome 

 in the present day. Shell cameos are much easier 

 to execute than stone cameos; hence, however 

 beautiful the design, they are much less valuable 

 than the latter. A good stone cameo, the size of 

 half-a-crown, with a simple head as device, is 

 frequently worth a thousand francs (40) ; whilst a 



