554 PALAEONTOLOGY OF ILLINOIS. 



some error, the locality and position given in the Iowa Eeport are 

 "Keokuk Limestone; Warsaw, Illinois." 



GENUS EUPACHYCKINUS. 

 EUPACHYCEINUS BoYDii, M. and W. 



Eupachycrinus Boydii, MEEK and WOKTHEN, 1870. Proceed. Acad. Xat. Sci., Pliila., p. 30. 



BODY much depressed, or twice and a half as wide as 

 high to the top of the first radials, rounded inward above 

 the second radials, and under to the very profound central 

 concavity below ; composed of thick, strong, slightly con- 

 vex plates. Base very small and deeply sunken in the con- 

 cavity of the under side. Sub-radials comparatively large, 

 convex, and curving upward above, and under below, and 

 then again upward into the concavity of the under side, 

 where each of them has a mesial indentation or notch ; each 

 presenting a general pentagonal outline, excepting two on 

 the anal side, which are modified for the reception of the 

 anal pieces. First radials about twice as wide as high, 

 convex, and equaling the sub- radials in breadth, all pen- 

 tagonal in form. Second radial pieces convex, about half 

 as large as the first, which they do not quite equal in 

 breadth, although they are in contact with each other all 

 around, thus giving a contracted appearance to the body 

 just above the first radials; each about twice as wide as 

 high, pentagonal in form, and bearing on one superior 

 sloping side an arm, while on the other there rests a smaller 

 secondary radial bearing two arms; thus making, as far as 

 can be seen, three arms to a ray, or if the same structure 

 exists in all the rays, fifteen to the entire series. First or 

 sub-anals rather large, nearly quadrangular in form, and 

 resting between the sloping upper sides of two of the sub- 

 radials, under one side of the first radial on the right, and 

 .connecting with the second radial on the left, but appar- 



