GENERAL GEOGRAPHIC AND STRATIGRAPHIC DISTRIBUTION. 



113 



SUMMARY OF ORDOVICIAN BRACHIOPOBA. 



The Ordovician Brachiopoda are summarized in two tables, one by genera and the other 

 by f amiUes : 



Summary oj Ordovician Brachiopoda hy genera. 



o Found only in tlie Ordovician. 

 Summary of Ordovician Brachiopoda by families." 



o This table includes all Ordovician species talcen up in the monograph. With the exception of three genera, one subgenus, forty-two 

 species, and one variety all of these pass up from the Cambrian. (See pp. 122-123 for a list of the Ordovician forms taken up in this monograph.) 



GENERAL SUMMARY OF CAMBRIAN AND ORDOVICIAN BRACHIOPODA. 



The following table gives a general summary of the genera, subgenera, species, and 

 varieties, both Cambrian and Ordovician, in each of the families taken up in this monograph : 

 General summary of Cambrian and Ordovician Brachiopoda. 



62667°— VOL 51, pt 1— 12- 



