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thus proving them later than the Shasta group, or even that exposed 

 in the old coal mine on Point Loma, San Diego. The Nautilus texanus 

 indicates a near approach to the Eocene, Aturia zigzag. From the 

 published lists, Dr. C. A. White considers these Chico beds. 



Several other Texan and Mexican species seem to occur, confirming 

 the belief in a free connection of the two oceans existing across North- 

 ern Mexico, if not Arizona, in the Cretaceous age. Further collections 

 may prove some of these to be distinct species. It is proper to mention 

 that Professor Davidson's party gave the first notice of Cretaceous 

 fossils on the Santa Ana Mountains to Professor Whitney, then State 

 Geologist, who directed Mr. Goodyear and myself to look for all fossil 

 localities during a rapid journey we were to make by wagon through 

 the Julian gold mines, and thence north to Los Angeles. On account 

 of the suspension of the Survey, no account of these and other dis- 

 coveries was published until 1888, when Mr. Goodyear gave his obser- 

 vations in the Report of the State Mineralogist, p. 335, including the 

 determinations of the geological age of the strata along the route as 

 shown by the fossils, etc. Alisos Creek was the only locality north 

 of San Diego where any Cretaceous (or Eocene) fossils were seen. 

 Limited time did not permit of much exploration, nor of making large 

 collections. 



Dr. C. A. White is of the opinion that the Cretaceous fossils of the 

 West Coast are all distinct species from those of the Atlantic Slope, 

 and that no connection between the oceans existed in North America 

 during that era. 



But the many species of fossils which are so closely allied as to 

 appear merely varieties of each other on the two slopes, and some even 

 identical, the near approach of Cretaceous strata together from each 

 side, and the general law of geology that the oldest formations contain 

 the most widespread species, seem strong arguments against such a 

 conclusion. The same theory was once held by Dr. Gould and others 

 regarding living species, but time has disproved it, and shown that 

 even the narrow barrier of the Isthmus of Panama did not exist until 

 the Pliocene epoch, at least as far as the evidence of Miocene fossils 

 then uplifted can be conclusive. 



