CRINOID GENUS SCYPHOCRINUS 7 



In no case can the stem be traced to the distal end ; all of them at a short 

 distance from the crown either pass under other crowns, or become enveloped 

 in the general mass of remains. Therefore we do not know the full length of 

 the stem, but this must have been considerable, since incomplete portions are 

 seen for distances of 18 to 30 inches, and the quantity of stem remains is very 

 great in proportion to the number of crowns. 



Intermingled with the crowns and stems are a number of Camarocrinus 

 bulbs; some of these are well exposed and appear of good size (PI. I, at 

 H and /), while in many cases only a part can be seen among the other objects 

 (PI. I, at K). All of them are considerably flattened, and some are fractured 

 from the pressure of the overlying mass of remains which was consolidated 

 into the compact limestone deposit forming the main thickness of the heavy 

 layer. For this reason none have the complete rotundity and undistorted form 

 of the West Virginia, southern Tennessee, and Oklahoma specimens, of which 

 the stems and crowns have been detached and swept away by currents, and the 

 bulbs left buried in the mud. But the broken condition of many of the bulbs, 

 and of some of the calices in contact with them, is very similar to that of the 

 fragmentary remains found by Mr. Braun in Benton County, Tennessee, which 

 undoubtedly came from a colony deposited under like circumstances to this one. 

 Counting broken ones, there are about 15 of these bulbs more or less visible 

 upon the surface as now exposed. This slab, of which a photograph is herewith 

 given (PI. I), is now installed for exhibition in the Hall of Invertebrate 

 Paleontology of the National Museum. 1 



In all there are about 50 of the bulbs to be seen in the material under 

 consideration. Most of them are well exposed on the lower surface of the 

 rock, and in general it may be remarked that in those areas where the bulbs 

 predominate in this condition crowns are scarce, and vice versa. Where they 

 have been lying side by side in the mud in close contact both are more or less 

 distorted or broken, as already explained; and it is evident that the bulbs in 

 their original condition were fragile structures, by no means so solid and rigid 

 as they appear when free ; on the contrary, their walls were relatively light, thin, 

 and porous, easily crushed and broken, a large part of their volume consisting 

 of compartments containing soft parts or water. 



In another piece from the same bed is a cluster of five bulbs within an 

 area of about one square foot; they are almost entirely free from stems or 

 other remains, and the matrix passes directly into the firm limestone, thus 

 indicating that they were near the edge of the colony; and when the forest of 

 crinoids went down before the destroying agency, whatever it was, the stalks 

 fell away from these roots, leaving them imbedded in the mud where they grew, 



1 Proc U. S. National Museum (Bassler), vol. 46, p. 59, 1913. 



