SYNOPSIS 



THE INVERTEBRATE FOSSILS 



OF THE 



TERTIARY FORMATIONS OF CALIFORNIA. 



In the following synopsis I have included all the species of 

 Tertiary fossils described from the West Coast, which have been 

 encountered during the progress of the Geological Survey, either 

 in California or in the adjoining State of Oregon. This is indis- 

 pensable, on account of the intimate relations existing between 

 the Tertiaries of the two States. 



The species which have been named, but not recognized or 

 rediscovered, are appended as a separate list at the end. Of the 

 latter, some will doubtless yet.be encountered, though the great 

 majority seem to be hopelessly lost. In many cases I have been 

 able to discover what was meant by a description in the Pacific 

 Railroad Reports, only by going to the typical locality, and by 

 that familiarity with the forms, which can only be acquired by 

 years of iutimate acquaintance and the study of series of speci- 

 mens such as amateurs rarely have the good fortune to accu- 

 mulate. "With the double advantage of all the facilities that a 

 government commission could afford, and of half a lifetime of 

 acquaintance with the peculiarities of the author's method of 

 working, I have failed in many cases to make out what was in- 

 tended by the meagre descriptions, and illustrations bad beyond 

 precedent, which are found in the Reports of the Pacific Railroad 



explorations. 



(67 ) 



