CRINOIDS AND P,LAST< >IDS. 101 



stant for the species, so as to be quite a reliable character for 

 identification. There are of course intermediate shades of color 

 between the lightest and darkest, but. as a general thing, speci- 

 mens of the same species have a uniform shade. 



The conditions of preservation of the LeGrand Crinoids are 

 such as to give unusual opportunities for examining the stems. 

 We found there a number of specimens having the stems intact 

 almost to the extremities of the roots and cirrhi. The stem in 

 all of them is short shorter than has generally been supposed 

 to be the case among Paheocrinoidea of this period. 



In all species >f the Camerata which have come to our notice, 

 the lower portion of the stem is provided with small irregular 

 cirrhi. given off at intervals singly from different sides. In a 

 species of Graphiocrinns, however, we found the cirrhi thickly 

 distributed all along the stem from the basals down : and a 

 similar structure we observed in certain species of Seapbiocrwns 

 lately found by us in Kentucky. It is also worthy of note that 

 in all our perfect specimens from LeGrand. as in those from 

 Burlington and CYawfordsville. the stem tapers to a tine point, 

 giving off rootlets in all directions, and that there is in no in- 

 stance any indication of an attachment by the column to a 

 solid substance. Similar observations have been made by us 

 upon detached steins ami roots, which at Burlington are found 

 in countless numbers, but among all the specimens which we 

 have examined there were only a few not a half dozen in all 

 showing a place of attachment, and in these exceptional c.-i 

 the stem terminated not in form of a plate, such as we find in 

 the Pentacrinoid larva of Antedon, but in a mass of flattened 

 roots. This seems to us of considerable importance as bearing 

 upon the question whether the Pakeocrinoids generally wen- 

 attached permanently, or perhaps in their adult state led a 

 kind of semi-free life, somewhat similar to recent species of 

 Pentacrinux (Challenger Report on the Stalked Crinoids. pp. 18 

 and 10. PL 10. Fig. 1.) Taking everything into considera- 

 tion, it seems to us the numerous small rootlets, spreading in 

 all directions lead to the conclusion that those Crinoids, 

 with but few exceptions, either lived upon a soft oozy bottom, 



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