4 UINTACRINUS: ITS STRUCTURE AND RELATIONS. 



in Logan and adjacent counties in western Kansas, within a I'adius of 

 less than twenty miles. 



The first result of the search begun by me was the unearthing of an 

 extensive continuation of the deposit in which Mr. Martin found the last 

 mentioned specimens. As this is by far the most important occurrence 

 of these Crinoids ever found, I will first give a somewhat full account of it, 

 and afterwards of the other localities known to me. 



Locality No. 1. — This is on the side of a deeply eroded ravine, 

 near the town of Elkader, in Logan County, Kansas. The fossils occur 

 in the upper part of the Niobrara Chalk, at about the junction of the so- 

 called yellow and blue shales. They were in place, covered by a con- 

 siderable thickness of overlying strata, and constituted the remains of a 

 very large colony. The deposit was in the form of a lenticular mass, 

 upwards of half an inch thick in the middle part, and thinning out on all 

 sides to the thinness of cardboard. It was approximately fifty feet lono- 

 on the outcrop, and extended into the hill for a maximum distance of 

 about twenty feet. A large part of the plate had been washed away 

 with the erosion of the ravine. It was not at all parts equally productive 

 of good specimens. The layer gained depth very rapidly as it passed 

 into the hill, and a large quantity of stripping had to be done to get at 

 the best part of it. After this about three weeks' time was consumed 

 in the work of tnking out and packing the specimens. The entire de- 

 posit was exhausted, the layer being followed until it thinned out on 

 all sides. In all upwards of twelve hundred specimens were obtained in 

 which more or less of the calyx is visible. The preservation of the 

 Crinoids from this locality varies considerably. In some parts they and 

 the matrix were almost white ; in others, tinged with oxide of iron to a 

 yellowish tint ; and in yet others the matrix was a bluish gray or 

 lavender. In the latter the preservation was the best, and the fossils 

 were not so much affected by chemical action. It is strange that within 

 a few feet of these the specimens should be greatly injured by some 

 chemical agency. 



The plate containing the Crinoids is of limestone, entirely composed 

 of the comminuted remains of these animals. It rests on a so-called 

 shale, consisting of a rather soft blue or yellowish calcareous mud, and is 

 overlaid by a somewhat similar layer, passing into quite pure yellow chalk 

 above. The shaly appearance is a condition of weathering, and is con- 



