1902.] AND ANCIENT GEOGRAPHY. 395 



Nevertheless, I am able to offer here a list that is quite large. 1 



1 Where no references are given, the facts are taken from Ortmann, in 

 Bronn's Klass. u. Ordn., Vol. 5, 1900, p. 1275, and from my unpublished revis- 

 ion of the respective groups for the " Thierreich." 



Identical species are printed in Small Capitals ; the most important forms, 

 where the genus is not found outside of American waters, are printed in italics. 



