48 



University of California Publications in Geology [Vol. 10 



graphic range of the Recent species gives the fauna a boreal aspect. 

 This evidence may he taken to support the view that the climatic 

 environment of the Los Angeles fauna was quite similar to that of 

 the San Pedro Pliocene fauna, the boreal character of which is equally 

 pronounced, and in which a near-shore character is indicated by the 

 lithology of the enclosing beds. 



Comparison with Related Faunas 

 It is obvious that the Los Angeles fauna must be referred either to 

 the lower Pleistocene or to the upper Pliocene. Before a more definite 

 correlation can be made it is necessary to compare percentages and 

 individual species with related faunas of recognized stratigraphic 

 position. Faunas with which relationships might be anticipated are 

 those derived from the Etehegoin, Merced, upper, middle and lower 

 Fernando, San Diego and San Pedro formations. 



Revised faunal lists 10 from various horizons in the Etehegoin 

 formation of the Southern San Joaquin area show that only eighteen 

 species of that formation are found in the Los Angeles fauna, and 

 these are for the most part such long-range forms as Natica recluziana 

 and Panope generosa. Three supposedly restricted Pliocene species, 

 Natica orbicularis, Turris mercedensis and Pecten healeyi, which are 

 found at the Los Angeles locality, occur in higher horizons of the 

 Etehegoin, and may indicate contemporaneity of later phases of that 

 period of deposition with the Los Angeles clays. In the main, however, 

 the Etehegoin fauna is decidedly earlier than that of the latter forma- 

 tion. Recent work has shown that the percentage of extinct species 

 in the fauna of the upper Etehegoin is between 58 and 60, while this 

 figure for the Los Angeles beds is 16.7. 



Several points of resemblance appear between the Los Angeles 

 fauna and the faunas of the Merced and Purisima formations of middle 

 and northern California. The latter faunas, which for the purposes 

 of this paper may be considered collectively, are typically boreal. 

 Northern types of pectens and mactras abound ; Natica clausa and 

 Macoma calcarea occur in many horizons, but the feature which stamps 

 the central California Pliocene fauna as incontestably boreal, is the 

 great abundance, both specifically and individually, of the Buccinidae. 

 This family is much less prominently developed in the southern fauna, 

 but is still sufficiently well represented to show an important similarity 

 between the two faunas. The upper Merced of the type locality of 



16 Nomland, J. O., Mss. in press. 



