— 37 — 



There are several other species believed to be new in the collection, 

 which are not perfect enough for description. It is a notable fact that 

 in both localities mentioned the conditions for perfect preservation of 

 specimens are much better than usual in the Cretaceous strata, as 

 little or no metamorphism has occurred, and softening of the shells is 

 quite moderate, though rather troublesome at the coal mines. The 

 presence of Conrad's "finger-post of the Eocene" {Cardita planicosta 

 Lamarck, as recently confirmed by Dr. White, from Oregon specimens) 

 abundantly, at Marysville Buttes, is a strong mark of the Eocene age, 

 and it was not found at the Huron coal mines, though it is given by 

 Gabb as from New Idria, Tejon Pass, etc. I found it myself at San Diego 

 in strata quite above the ammonite-bearing coal mine, and unconforma- 

 ble with it. 



ON COLLECTIONS BY H. W. FAIRBANKS. 



After the preceding remarks were written, and while the new species 

 were being prepared for illustration, Mr. Fairbanks brought in his 

 large collection from Cretaceous (Eocene?) and Tertiary strata of San 

 Diego County, containing large additions to the known lists from that 

 county, and a considerable number of new species in the Cretac-Eocene 

 divisions. Having carefully avoided mixing those from various locali- 

 ties, Mr. Fairbanks' collections proved of great value as evidence in 

 the much-debated question as to the continuity of the two forma- 

 tions referred to, and I have therefore tabulated the results, so as to 

 show how far each species is found to be contained in the true Cretaceous 

 or ammonitiferous beds. The extent of the Cretaceous B, or Eocene 

 strata of different authors, is not great in that county, but they are 

 very productive of species of fossils, and therefore seem to indicate the 

 lapse of a long period of time during their deposition — as long, perhaps, 

 as the whole of the Tertiary and Quaternary epochs combined, as 

 demonstrated by the marine deposits hitherto known on this coast. 

 The only " Cretaceous " fossils previously published as from San Diego 

 County were those which I collected, described by Mr. Gabb in the 

 Palaeontology of Whitney's Geological Survey of California. They 

 were obtained: First — From a shaft sunk for coal near the lighthouse 

 on Point Loma; a Heteroceras, preserved and presented by E. W. Morse 

 Esq. Second — Baculites chicoensis, found by me loose on the surface 

 near the lighthouse (where I searched unsuccessfully for others). 

 Third — A few species presented by Mr. Morse from an unknown 

 locality, and which were perhaps in part Tertiary. Fourth — Over 20 

 species collected by me at one locality, a branch of Rose Canon, seven 

 miles north of Old San Diego, but which were all included by Gabb as 

 Cretaceous fossils. It must also be noticed that in Vol. I of Pal., p. 

 220, Mr. Gabb tabulated twenty-one of these, and gives seven of them 

 4p 



