256 T. W. STANTON — SHASTA AND CHICO FAUNAS. 



The specific conclusions reached may thus he summarized : There is 



no fauna] break any where in the entire series of strata- that have been 

 referred to the Shasta and Chico formations. Certain portions of the 

 series are characterized by the abundance of particular species, e. g., 

 AuceUa in the lower beds and several species and genera of ammonites 

 in the Horsetown division ; but these sub-faunas are so bound together 

 by connecting species that they cannot be regarded as really distinct, 

 and I have therefore adopted Mr Diller's suggestion and called the whole 

 the Shasta-Chico fauna. The age of this fauna, or at least of the portion 

 found in the Horsetown beds, seems to be not more recent than the 

 Cenomanian. 



