14 TRIASSIC FISHES AND PLANTS. 
are peculiarly barren of fossils. They are generally reddish sandstones, con- 
elomerates, and shales below, with a series of highly colored indurated marls 
or fine-grained calcareous sandstones above, frequently charged with salt 
and sometimes including extensive sheets of gypsum. The sandstones are 
also conspicuously cross-bedded, and it is evident that the whole series was 
deposited in a shallow sea, swept by strong currents or high tides, and that 
bays, estuaries, or lagoons were formed at various times, in which the water 
was evaporated and its salt and gypsum were precipitated. These condi- 
tions were unfavorable to the presence of animal or vegetable life: as con- 
sequences, we rarely find any fossils in the beds, and the iron they contain 
is peroxidized, imparting to them their characteristic red color. This great 
sheet of Triassic rocks originally extended to the Wasatch Mountains, which 
formed the western shore of the sea in which they were deposited. 
Passing over hundreds of miles where these Triassic rocks were just 
beneath the surfuce and freely exposed in cliffs and stream beds, I have 
sought for months in vain to find in them any traces of life; yet in two 
localities which I visited I was more successful, and from a third I have 
received a large collection of fossil plants. These localities are San José, 
near Pecos, in New Mexico, the old copper mines above Abiquiu, and Los 
Bronces, on the Yaki River, in Sonora. At the first locality are found Walchia 
and Calamites below, which mean Permian, and in softer beds of sandstone 
above—doubtless Triassic—impressions of fern fronds too indistinct for de- 
termination. 
In the roof shales of the old copper mines near Abiquiu plants are 
abundant, but the number of species is small. Of these the most comnren 
and conspicuous is an Ofozamites with broad truncated pinnules, which I 
have called O. Macombii; another cyead less common is a Zamites (Z. occi- 
dentalis Newb.), while twigs and cones of Pachyphyllum are occasionally 
seen. At Los Bronces the number of species is much larger, and we find 
among them several which occur in North Carolina, and one of those ob- 
tained from Abiquiu (Otozamites Macombii). The Carolina species are Pe- 
copteris bullatus Bunbury (Mertensides bullatus Fontaine), Pecopteris Julcatus 
Emmons (Laccopteris Emmonsi Fontaine), and Tceniopteris magnifolia Rogers. 
These indicate a parallelism between the plant-bearing beds of the Atlantic 
