INVERTEBRATES. 317 



GENUS LECYTHIOCKimiS, White. 

 LECYTHIOCRINUS ADAMSI, Worthen. 



PI. XXXI. Fig. 8. 



Lecythiocrinus Adamsi, WORTHEN, Feb. 1882. 

 Bulletin No. 1, of the Illinois State Museum of Natural History, p. 37. 



Body of medium size, irregularly subovoid, slightly pentalobate, 

 as seen from above or below, from the protuberance of the radial 

 plates, and composed of smooth and rather thin plates. The base 

 is convex, and occupies about one-fourth the entire length of the 

 body. 



Subradials a little longer than wide, with an angular prominence 

 just above the middle of each plate, extending from the center to 

 the upper margins. 



Radials about half as large as the subradials, length and width 

 about equal, triangular below, the angles fitting into the depressions 

 between the subradials. They are all surmounted by a small semi- 

 circular arm-facet, from which a shallow groove extends to a central 

 opening in the summit. 



Just above the summit of one of the subradials, and in the lat- 

 eral angles of two of the radial plates, there appears to have been 

 a circular opening, rather larger than the arm-facets, which is now 

 filled with stony matter, and whether this is an anal opening, or 

 an accidental break in the test of the body, is a question to be de- 

 termined from additional material. Columnar facet scarcely larger 

 than that for the reception of the arms. Arms and column un- 

 known. 



We take pleasure in dedicating this unique fossil to Mr. W. H. 

 Adams, of Elmore, Peoria county, who found it on section 18, town- 

 ship 11 north, range 6 east, Peoria county. 



It is from about the horizon of Coal No. 8 of the Lower Coal 

 Measures. 



No. 2,468 of Illinois State collection. 



