MICROSCOPIC ORGANISMS AT MONTEREY. 
81 
extend much further in all directions under the vegetation. The white, chalk-like earth con¬ 
trasts strangely with the green leaves above it—it seems as little fitted for vegetation as a lime 
heap. The removal of the loose fragments lying upon the surface revealed the existence of 
numerous lines of stratification as thin and regular as the leaves of a book. This white outcrop 
appears to be the principal or thickest stratum of the series, and it is near the top of the hill, 
but lower down, the white earth alternates with silicious beds, which are peculiarly compact and 
very finely stratified. Some of these layers are excessively hard, and the rock breaks with a 
conchoidal fracture, like flint or semi-opal. 
The whole series of strata are parallel, but not horizontal, being inclined in a direction south 
of east, or nearly southeasterly, at an angle of from twenty to thirty degrees. The following is 
the succession of the beds, from the upper stratum downwards to the lowest point which was 
examined. The thicknesses given are approximations : 
SECTION OF INFUSORIAL STRATA AT MONTEREY. 
Feet. 
1. White silicious earth, light, and charged with infusoria......50.0 
2. Compact and silicious, probably bituminous___ .3 
3. White and earthy, resembling No. 1........-. 1.0 
4. Compact, silicious, dark-colored, and bituminous.__........6 
5. White and earthy, like No. 1......... 12.0 
6. Compact, silicious, dark-colored, and bituminous_..._ .6 
7. White and earthy, like No. 1._______ 2.0 
8. Compact, flint-like, very hard, and nearly white. No very thin layers_ 2.0 
9. White, earthy, and silicious, like No. 1. In very thin layers, intercalated with thin sheets of compact and 
semi-opaline silica...........10.0 
10. Compact and silicious. Hard and drab-colored___ 3.0 
11. White and earthy, similar to No. 1. (The thickness of this stratum was not ascertained ; it extends down¬ 
wards under the chamizal for a long distance.)____,._____ 
It will thus be seen that there is one bed of microscopic organisms fifty feet in thickness. 
This is believed to be much less than it is in reality. The underlying beds, which are similar 
in their appearance, are probably equally fossiliferous ; but this has not been demonstrated by 
examination. Their thicknesses are, respectively, 1, 12, 2, and 10 feet, which, added to the 
thickness of the upper stratum, make a total of seventy-five feet. This is exclusive of the com¬ 
pact silicious strata, which are presumed to be also fossiliferous. 
The white infusorial earth contains much clay, and is very tough. It is easily cut or carved 
into any form with a knife, and may be sawn into square blocks with great ease. Unless 
crushed to powder on the surface, it does not soil the fingers. It absorbs water rapidly, but 
does not easily break down in it, or soften like clay. 
A fragment of the upper stratum was forwarded to Professor J. W. Bailey, of the United 
States Military Academy at West Point in 1854; in his letter of acknowledgment, he states that 
it is “ rich in marine diatoms ; the seive-like discs belong to the genus Coscinodiscus, but there 
are many other very beautiful forms present. It is singular that the deposit contains some 
species which have only recently been detected as living species in the Pacific. It has quite a 
modern look, and contains many species which could only have grown in shallow water.” 
A full series of specimens was obtained, and, together with one large block of the white earth, 
was placed in the hands of Professor Bailey for examination. He has found many very inter¬ 
esting forms, but his observations on them have not been received. Figures of many, drawn by 
Professor B., will be found on Plate XII. 
The compact silicious layers, intercalated with the porous infusorial earth, are very peculiar. 
