Geological Reconnoissance in N. M. — Herrick. 335 
here is fossiliferous with a fauna of Permo-carboniferous age, 
including- such species as Meekella striatocostata, Aviculopecten 
occidentaHs, Terebratula bovidens, the large form or variety of 
Athyris argentea, Productus punctatus, Productus semireticu- 
iatus, Productus longispinus, Chonetes granulifera, and many 
more. 
About twelve miles farther north is another group of 
springs which will some day be famous for its curative pow- 
ers. The sulphurs occupy a basin in the heart of a trachyte 
country and is an intensely volcanic neighborhood. A short 
distance to the south-east is a most curious crater, an area of 
oval form and about one third of a mile in diameter, level as 
a floor and surrounded on two sides- by the wall of the La Jara 
mountain, while the remainder of its periphery is formed by a 
low dam of lava. The area is partly covered by a fine growth 
of pine timber. The natives call this crater "el cajete," or the 
washtub. It is from this region that the great flows of ob- 
sidian and obsidian breccia have evidently been derived. In 
the basin of the sulphurs themselves the walls are chiefly 
formed of white tuff and about twenty springs of the most 
various character bubble up in the centre of mounds of their 
own making. Many of these are highly charged with sul- 
phurous oxide and deposit sulphur in large quantities. Oth- 
ers are highly carbonated. The deposits of sulphur are of 
great extent. Though the accommodations are as yet some- 
what primitive and access very difficult, the result of treat- 
ment in the case of many kinds of disease are often very re- 
markable. 
As one passes south from Perea the Permo-carboniferous 
soon dips out of sight and the red sandstones of what we have 
called the red or saliferous series of New Mexico assume the 
important place in the abrupt river bluffs. This series is 
capped with several distinct layers of tufa. Tertiary beds are 
exposed near the town of Jemes and the other Indian pueblos 
farther south and these are continuous with the Santa Fe marl 
below Silla or Zia. Extending south from the south end of 
the Jemez mountains is an elevated plateau of Permian rock 
consisting of reddish limestone and sandstone much mingled 
with gypsum. Although not fossiliferous at this point we 
have elsewhere in the territory found the lower member of 
