THE CRAWFORDSVILLE CRINOIDS. 557 



the right bank of Sugar Creek, one mile north of the city of Crawfordsville, 

 Montgomery County, Indiana. It extends up and down the creek a distance of 

 about thirty rods, cropping out towards the northeast, and pitching under the 

 creek towards the southwest. How far it extends into the bluff is not known, 

 but probably not very far. This small space of four or five acres seems to be 

 the only spot in Montgomery County where these fossils are found, and the only 

 one in the world where they are found in such abundance, and in such favorable 

 conditions for excavating and preparing them for the cabinet. For some reason 

 this seems to have been a favorite locality with these remarkable animals of the 

 carboniferous seas. 



Geologically, the beds belong to the Keokuk Group of the sub-carboniferous 

 period, and are composed of argillaceous shale, loose and much broken at the 

 top, but more compact and solidified below. The rock is stratified, and indicates 

 aqueous deposit in quiet waters. In color the strata resemble French gray, or 

 light lead color tinged with blue. The upper strata for several feet have been 

 bleached to a light brown by infiltrations of the surface-water. The strata vary 

 in thickness from one to three feet, and the hardest of them, owing to their shaly 

 character, may be quite easily split into slabs of various thicknesses. 



Remains of crinoids and other fossils, decayed and worthless, are found 

 quite abundant at the very summit of the shale, and continue to the depth of 

 fifteen feet. The next twenty feet are almost entirely destitute of fossils of any 

 kind, and the cessation of life above and the beginning of life below are very 

 abrupt. The first crinoids, sufficiently well preserved for cabinet collections, are 

 found at a depth of thirty-five feet from the top of the blufl", and most of this 

 distance the rock must be blasted. Below this point, crinoids have been found 

 at different intervals as far as excavations have been made. They do not occur 

 in all the strata, neither are they uniformly scattered through those in which they 

 do occur. For the most part they seem to have lived in schools, or clusters, 

 sometimes crowded so closely together as to be lying one upon another five or 

 six deep. In a slab measuring three feet by two and a half, taken from one of 

 these clusters, and the matrix so removed as to expose the fossils in their natural 

 position, there were eighty crinoids besides several other fossils of different genera 

 and species. The crinoids with their curious heads, and their long stems cross- 

 ing and recrossing each other, lay stretched out one above another in every 

 direction. Among the crinoids in these clusters are frequently found moUusks, 

 trilobites, conularia, archimedes, pentremites, ongchasters and protasters, and 

 some others, "^strangers to the writer. 



These clusters usually extend but a few feet, and generally terminate abruptly, 

 and where another such shall be found, is a matter of chance, involving much 

 time and hard labor. An occasional crinoid, usually of larger size and more 

 perfect than usual, may be met with in the intervals between these clusters, but 

 in the intervening spaces between the bearing strata, which vary from one to 

 several feet, we may look in vain for any crinoids fit for the cabinet — nothing 

 but fragments of heads and stems, evidentlv the work of mollusks. 



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