A Nematoip Worm 1n AN Ecc. By Danret J. Troyer. 
THE Grontocic RELATIONS OF SoME St. Louis Group CAVES AND SINKHOLES. 
By M. N. Exrop, M. D. 
Before discussing the geologic relations of the caves, sinkholes and 
subterranean channels of St. Louis limestone to each other and to the 
strata in which they occur, it will be necessary to define the limits of that 
formation in Indiana. The Warsaw bed, as exposed at Spergen Hill and 
elsewhere, is recognized as the equivalent of the Bedford odlitic limestone, 
and the lowest member of the St. Louis. The fossils found in it are 
abundant and characteristic, and its lithologic peculiarities obvious. But 
the upper limits of the group are not so well settled. When Prof. James 
Hall first fully defined the Kaskaskia group, as seen on the banks of 
the Mississippi River, he included as its lowest member a stratum of 
sandstone. In Indiana the first sandstone stratum above the St. Louis has 
been recognized as forming a part, at least, of the Kaskaskia group, but 
not always as its lowest limit. The classification of Prof. Hall* was first 
applied to the geologic formations of Indiana by ex-State Geologist E. T. 
Cox, in 1872, in a report on the geology of Perry County,+ in which he 
made the first sandstone above the St. Louis the base of the Kaskaskia 
group, and by the law of priority, his identification should be recognized 
unless there is sufficient reason for a change. Since that time the divid- 
ing line has been placed at a lower level; one observer finding it at a 
small coal seam in the limestone strata;t others at the top of the upper 
fossiliferous chert member of the St. Louis; and others have included 
with the Kaskaskia extensive strata of limestone under the sandstone, 
without indicating by a section or otherwise where the one terminated 
and the other began.§ Much of this confusion has grown out of an effort 
to limit the upper St. Louis group to such strata only as contain Litho- 
strotion canadense Castelnau and L. proliferum Hall, characteristic fossils 
* Hall’s Geol. of Iowa, pt. 1, p. 109, 1858. 
+ Geol. Sur. Ind., 1872, pp. 76, 77. 
tGeol. Sur. Ind., 1873, p. 365; 1878, pp. 305, 425. 
{ Geol. Sur. Ind., 1875, pp. 207, 216. 
2 Geol. Sur. Ind. 1895, pp. 231, 232; 1896, p. 300. 
