PAPERS READ BEFORE PACIFIC COAST SECTION 129 



The following paper was read by title : 



THE BIOGENETIC LAW ILLUSTRATED IN THE DEVELOPMENT OF FOSSIL 



CEPHALOPODS 



BY JAMES PEBRIN SMITH 



(Abstract) 



Recapitulation is discussed and illustrated and examples of unequal accele- 

 ration pointed out. Arrested development and retardation are discussed as 

 factors in the biogenetic law. Cases of convergence are brought forward and 

 their bearing on orthogenesis touched upon. The conclusion is reached that 

 imperfect recapitulation is all we may hope to find in the ontogeny of any 

 highly organized group. 



FAUNAL RELATIONS OF TILE UPPER NEOCENE IN THE SARQENT OIL FIELDS, 



CALIFORNIA 



BY BBUCE MAETIN 



(Abstract) 



The results of recent work in this field and the close faunal relations with 

 the Etchegoin formation of the Coalinga region were discussed. 



Discussion 



Mr. Lawson called attention to Mr. W. F. Jones's work in this region, saying 

 that Mr. Jones presented the first evidence of marked orogenic disturbance 

 in the time between the Monterey and the Etchegoin- San Pablo deposition in 

 central California. 



Mr. Clark spoke of the great transgression of the Etchegoin sea after Santa 

 Margarita time. 



Mr. Anderson thought the Etchegoin of the Sargent locality was very likely 

 directly connected with that of the Coalinga region. 



Mr. Merriam emphasized the close relationship between the Purissima and 

 Etchegoin formations, as shown by their fossils. 



MONTEREY SERIES ON THE SOUTH SIDE OF MOUNT DIABLO, CALIFORNIA 

 BY W. S. W. KEW AND R. C. STONEB 



(Abstract) 



The Monterey series of this region has a thickness of 1,800 feet, consisting 

 of conglomerates, sandstones, and shales; the lower part is quite conglomerate, 

 but there is no evidence of angular unconformity with the underlying Tejon. 

 The Monterey series is here unconformable beneath the San Pablo. A con- 

 siderable fauna has been collected showing that both Upper and Lower Mon- 

 terey time is represented. 



IX— Bull. Geol. Soc. Am., Vol. 24. 1912 



