340 CALIFORNIA ACADEMY OF SCIENCES. 



about a dozen are recognizable, and on account of cer- 

 tain fossiliferous beds which fringe its base in places. 

 The main body of the hill is composed of the Monterey 

 series, with only gentle dips as far as seen. The dips 

 vary somewhat, but are most common to the southeast. 

 These strata were not fossiliferous where examined, but 

 some pectens were found in one of the fragments in a 

 conglomerate near the lighthouse. These strata were> 

 thought by Trask* to be Cretaceous, though he had 

 '* some hesitancy in placing these rocks so high up in the 

 geological series." Later Dr. Antisellf correlated them 

 with the bituminous or Monterey group. 



The fossiliferous beds on the flanks of the hill were 

 called by Conradt "recent or post-Pliocene." In Dr. 

 Cooper's list of fossils they are referred to as Quater- 

 nary. § In 1874, ^^- ^- ^- Dall published a list of sixty- 

 nine molluscan forms from a well in San Diego, of which 

 he states,! "The age of the deposit, in general terms, 

 may be taken as Pliocene." In 1892, in the correlation 

 paper on the Neocene, he says:1I "It appears that on 

 Deadman Island, near Point Fermin, at least three dis- 

 tinguishable strata appear, the uppermost of which is 

 certainly Pleistocene, while the others are Neocene, and 

 the middle layer probably Pliocene." 



As Deadman Island is, is all probability, only an outlier 

 of San Pedro Hill, the middle layer on the hill may be 

 included as referred to the Pliocene by Dr. Dall. This 

 state of things is recognized by Prof. Lawson, who upon 



* Proc. Cal. Acad. Nat. Sci., 1855, p. 93. 



t Pacific Railroad Reports, vol. vii, p. 77. 



t Pacific Railroad Reports, vol. vii, p. 190. 



^7th Ann. Rep. of State Mineralogist, 1888, pp. 227 et seq. 



II Proc. Cal. Acad, of Sci., vol. v, pp. 296-299. 



•[[U. S. Geol. Surv., Bull. No. 84, 1892, p. 216. 



