164 
GEOLOGY. 
scarcely be broken without fracturing one or more of them. The shells were perfectly pre¬ 
served, and when broken out, looked almost as fresh as if recently taken from the water. They 
were neither stained nor softened. 
According to Mr. T. A. Conrad, the period of the Eocene is unequivocally represented hy 
these fossils. He describes fifteen species : Cardium linteum, Dosinia alta, Meretrix Uvasana, 
M, Californiana, Crassatella Uvasana , G. alta , Mytilus humerus, Gardita planicosta, Deshayes, 
Natica cetites, N. gibbosa, Lea, N. alveata, Turritella Uvasana, Volutatithes Galiforniana, Busy- 
con? Blakei, and Clavatula Californica. Eleven of these are regarded as new, and they are all 
described in Mr. Conrad’s report, Appendix, Article II. Figures are also given on Plate II. 
It is an interesting fact that three of the species are indentical with well-known forms of the 
Atlantic slope. Mr. Conrad’s observations on these fossils are exceedingly interesting, and for 
convenience are repeated here. “ The Eocene period is unequivocally represented by the beau¬ 
tifully perfect shells from the Canada de las Uvas, which, though not found in situ, are evi¬ 
dently derived from strata occurring on the Pacific slope of the Sierra Nevada. This is very 
remarkable, inasmuch as three species correspond with forms of Claiborne, Alabama, and seem 
to indicate a connexion of the Atlantic and Pacific oceans during the Eocene period. The vast 
distance between the two localities will account for the general distinction of species, and it was 
indeed an unexpected result to find any identical. If I had imagined any eastern species to 
occur in California, it would have been the very one which does occur, and apparently in abund¬ 
ance—that ‘finger-post’ of the Eocene, Gardita planicosta —a fossil of the Paris basin, and also 
abundant in Maryland, Virginia, and Alabama. This species originated and perished in the 
Eocene period, and is so widely distributed that it may be regarded as the most characteristic 
fossil of its era.” We thus find an identity of fossil species in nearly the same latitude, but 
separated by a distance of over 2,000 miles, and on the opposite sides of lofty mountain chains. 
Although these fossils were not taken from the sandstone strata which have been described, 
there is little doubt that they were broken from a prolongation of the same series. Their source 
could not be found in the Canada de las Uvas near the line of exploration, and it was probably 
further west, along some of the side ravines. 
It is very desirable that further explorations should be conducted in that region, and the 
locality of these beautiful fossils ascertained if possible. It will doubtless prove exceedingly 
rich in interesting species, and, judging from the per-centage of new species among those pro¬ 
cured from one block hardly a cubic foot in size, we may expect valuable additions to fossil 
conchology to result from its examination. 
Several specimens of a compact sandstone were brought to me by one of the party from the 
vicinity of the pass of San Amedio. They contain fossils of the genera Gytherea and Tellina. 
OCOYA CREEK—MIOCENE. 
The most extensive Miocene deposits examined during the course of the survey were at the 
base of the Sierra Nevada, around the Depot Camp, at Ocoya or Pose creek. In travelling 
southward towards the Tejon, smooth, rounded hills were encountered soon after leaving Moore’s 
creek, and became more elevated and numerous beyond White creek. The formation, however, 
which appears to be well represented by the fossils of Ocoya creek, extends in a continuous belt 
along the base of the Sierra Nevada, from White creek to Ocoya creek, and beyond it for many 
miles to the southward, forming high banks on both sides of Posuncula or Kern river, and even 
extending in a narrow strip to the Tejon* This belt of horizontal strata is lenticular in form, 
