194 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
This analysis may be compared with those of the odlitic hematite 
ore of the Clinton of New York, listed by Newland and Hartnagel 
(Bull. 123, N. Y. state mus., 1908, p. 62). 
1 2 3 . 4 5 
FeO; 69.17 42.97 79.98 63 .00 71.82 
SiOz 11.457. DO dae 9.98 12 6e. 11.34 
Al,O3 3.92 4.13 - 2 4: 5.45 3.91 
MnO 19 Pt tr. 45 1.63 
OD cor rchcc eae BOT, 154 6:2 3.97 
MgO iy | 1.96 ‘3 aw ed 2.21 
S .28 837 2s 
P.O; 1.726 1.534 1.239 1 2.096 
Comparing these analyses, it will be noted that the “linsen” have 
about the same iron content as some of the Clinton odlites, and about 
the same amount of clay, manganese, and phosphates, but less silica, 
lime, and magnesia. The high silica content of the Clinton ore is due 
to the presence of nuclei of sand in the spherules, whereas the nuclei 
of the linsen, when such can be observed at all, seem to be calcitic 
fragments of fossils. | 
The linsen have much the same size and shape as the spherules in 
the odlitic Clinton ore, most of them being from .5 to 1 mm. in diameter, 
and somewhat flattened or lentil shaped. This flattening, in the case 
of the Clinton odlites, has been ascribed to pressure, but in the case 
of the linsen it seems to be the original form, for, while these dises 
often lie parallel to the bedding, very large numbers of them do not, 
but are imbedded at all angles. 
The mode of occurrence of these linsen has some bearing upon the 
rival theories of the origin of the odlitic sedimentary hematite ores. 
The view put forward by Shaler was that they were replacements of 
original limestone effected by the circulation of ground water, while - 
C. H. Smyth, Jr., considers these ores to be original sedimentary 
deposits. The Russian occurrences are explainable only by Professor 
Smyth’s views, since: — 
First; the linsen occur in a limestone which is not otherwise odlitie. 
Second; the linsen occupy definite layers which can be traced 
laterally some 300 miles through a series of gentle undulations, always 
maintaining a definite horizon, as shown by evidence of fossils, and 
without any relation to the present water table. 
Third; the lower linsenschicht passes laterally into a true conglomer- 
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