F. Springer—Burlington Limestone in New Mexico. 103 
the oceurrence of the Crinoids at a few good exposures within 
a limited area, it is not improbable that they may be considera- 
bly modified by further researches, should other exposures be 
discovered in the same region. 
he relations of bed 9, of the Lake Valley section, are not 
so clear. It exhibits in some places irregular layers of a light- 
colored semi-crystalline limestone, largely composed of the stem 
joints and plates of Crinoids, that strongly resembles’ the Upper 
Burlington. But among the few fossils discovered therein, I 
was unable to find any characteristic upper bed species, with 
the possible exception of two fragments of fish teeth—a Cho- 
matodus and a Petalorhyncus—which are common forms in the 
‘Upper Burlington, but have not to my knowledge been as yet 
observed in the Lower. Further examinations may reveal a 
more chararteristic Upper bed fauna, but at present I am dis- 
posed to think this bed represents the cherty passage beds 
between the Upper and Lower Burlington. 
The strata below No. 7 may be referred, in part at least, to 
the Kinderhook group, but I cannot determine the line of sep- 
aration, because these strata, as well as those of No. 7, are 
mostly obscured by their own debris and the éalus of the 
heavier beds above. The molluscan fauna of the lower part of 
0. 7 is in many respects similar to that of the Choteau Lime- 
Stone. It may be that these mollusks were associated with 
many species of Lower Burlington Crinoids, and that in this 
case, as in some localities in Iowa, they have continued to flour- 
ish longer, and appear higher in the beds, than at the typical 
locality of the Choteau. Bed No. 8 is similar in appearance 
to No. 5 of White's section at Burlington (Bost. Jour. Nat. 
Hist., vol. vii, p. 215), and Nos. 1 and 2 are apparently not un- 
like No. 1 of that section. A’ Rhynchonella found in form of 
casts in No. 3 very strongly resembles White’s A. pustulosa, 
and a small Spirifer, similar to his S. solidirostris, was collecte 
from No. Sufficient material has not yet been obtained 
from the beds below No. 7, for a satisfactory determination of 
SO 
was called the “upper horizon,” a blastoid of the genus Gran- 
atocrinus, Considering the information we have of these local- : 
ites, in connection with what has been observed at Lake = 
