6 4 



SMITHSONIAN INSTITUTION 



Vulsella lingulata Lam. (15) 156. 

 Vulsella major "(15) 156. 

 Vulsella minor (16) 156. 

 Vulsella spongiarum Lam. (16) 156. 



Xancus perversus (1688) 134. (== 

 1686 var.) 



Xancus punctatus (1686) 134. 

 Xancus pyrum (1682) 134. 

 Xenophora, see Astraea, 1040-42. 



Yoldia sp. ind. (343) 185. 



Note. — This index is made from the original edition of 1798; the photo- 

 typic reproduction has a few obscurities which will account for a few 

 apparent but not real discrepancies. 



