208 University of California Publications in Geology [Vol.7 



characterized by a definite fauna, representing a definite time 

 interval. Its correlation with formations in other parts of the 

 State is hinted at, but not definitely stated. Anderson refused 

 to compare it with the "Vaquero sandstones" of the Salinas 

 Valley, because they "lack thus far any faunal description" and 

 Fairbanks' correlation of these with "beds occurring south of 

 the Santa Lucia Range is not supported by any faunal evidence. ' ' 

 He made no reference to the Pescadero series, nor in his later 

 publications does he ever refer to it again. Nor is it used by 

 any other writer. 



California Formations and Faunas, Arnold, 1906.- — In 1906 

 Arnold published a monograph on the "Tertiary and Quater- 

 nary Pectens of California," 18 in Part I of which he presented 

 the California post-Cretaceous geologic column, defined briefly 

 the standard formations, listed their faunas and indicated their 

 supposed characteristic species. 



He emphasized the fallacy that was discussed above (p. 204) 

 by making the "Vaqueros sandstone" 4 " a definite formation 

 underlying the "Monterey shale" and equivalent to the " Aga- 

 soma zone." From the list of localities given it is evident that 

 he considered the lower Miocene beds of Contra Costa discussed 

 by Merriam, the Salinas and Los Vaqueros Valley beds described 

 by Hamlin, the sandstones of the San Luis region discussed by 

 Fairbanks, the Temblor beds of Anderson, the Santa Cruz Moun- 

 tains beds previously described by himself and Haehl, the Poso 

 Creek beds (Ocoya Creek beds of Blake and others) of the Sierra 

 Nevada foothills, and various deposits in southern California, as 

 being Vaqueros or representing the horizon of the Agasoma zone. 



He described the "Monterey shale" as a "very characteristic 

 shale formation . . . underlain conformably by the Vaqueros 

 sandstones at most localities, but at a few it rests directly upon 

 older rocks." The faunal list is made to include some forms 

 "found both below and above it, or in its included sandstones." 

 Of the definitely determined species given, it may be noted that 



« U. S. Geol. Surv. Prof. Paper, no. 47 (1906). 



49 From this time forward, without any particular explanation, ths 

 form Vaqueros replaces Vaquero in the literature, apparently to conform 

 to some rule of etymology. 



