NO. 2009. A FINE SLAB OF FOSSIL CRIN0IDS—BA8SLER. 59 



Four large slabs ranging from 500 to 1,500 pounds weight each 

 and a number of smaller pieces were selected, the whole weighing 

 4,500 pounds. Two of the slabs fit together, forming a single one of 

 about 4 by 7 feet, containing the most important specimens. This 

 is the slab now on exhibition in the United States National Museum. 

 The remaining specimens have been prepared and form a part of the 

 study series. 



The locality was a number of miles distant from any station or 

 landmg, and it was necessary to transport lumber to make strong 

 packing cases for the slabs, embedding them m plaster to insure the 

 specunens from injury m handling. A chute was then constructed 

 to slide the cases down with ropes and tackle from a rock levee to 

 the water's edge, about 35 feet distant, where they were shipped on 

 a passmg river steamboat. Upon their arrival at the National 

 Museum it was necessary to clear away the adherent clay with fine 

 tools before the specimens could be seen or studied. In addition a 

 large amount of time was consumed in removing the more or less 

 hard calcareous matrix composed of innumerable arm and pinnule 

 joints forced down between the arms of the specimens and firmly 

 cemented by pressure. 



The principal slab, of which a portion, one-sixth natural size, is 

 shown on plate 1, contains 18 complete crowns, several of them with 

 the stem attached for part of its length. Some have the calyx fairly 

 rotund, but most of them are considerably flattened and often much 

 distorted by contact with the Caniarocrinus bulbs noted below. AU 

 have the strong, many-branched arms intact and often upward of 

 12 inches long. Two of the smaller but more complete calices, one- 

 half natural size, are shown on plate 2. Besides these crowns sev- 

 eral sets of arms are partly visible, belonging to calices which are 

 entirely buried, either under other individuals or m the limestone 

 matrix, which becomes fu-m and hard a short distance inward. Some 

 parts of the slab are covered with a dense mass of stems lying parallel 

 like stalks of grain in a sheaf, and many of the crowns lie with their 

 arms pomting in the same direction, as if they had fallen over in the 

 mud at the same time under the common impulse of a gentle current. 

 Intermmgled with the crowns and stems forming the chief remaining 

 portion of the crowded surface are numerous Camarocrinus bulbs; 

 some of them are well exposed and appear of good size, while in 

 many cases only a part can be seen protruding among the other 

 objects. All of them are considerably flattened and some much frac- 

 tured from the pressure of the overlying mass of arms of the compact 

 limestone deposit forming the main thickness of the heavy layer. 



This slab has been mounted on a flat-topped glass-covered base 

 and has been mstalled at the west end of the hall of Invertebrate 

 Paleontology. Here the specimen serves a twofold purpose — ^first, 

 in showing one method of fossilization, and, second, as an introduc- 

 tion to the biologic exhibit of fossil crinoids. 



