448 PALEONTOLOGY OF ILLINOIS. 



pentagonal in form, and supporting on their superior 

 sloping sides the first arm pieces, which are quadrangular, 

 slightly constricted on each side, and a little wider than 

 long; arms beyond these simple (as far as they can be 

 traced in the specimen), two to each ray, or ten in the 

 whole series, and composed of somewhat shorter, quadran- 

 gular pieces, provided with a well defined anibulacral fur- 

 row within. Surface merely finely granular. 



Hight of body to the top of the first radials, 0.12 inch; 

 breadth, 0.23 inch. 



This little species will be readily distinguished from those already 

 known from the Coal Measures by its much more depressed, rapidly 

 expanding body, as well as by its proportionally longer and constricted 

 second radial pieces. 



Locality and position Lower division of the Burlington group, at 

 Burlington, Iowa. Lower Carboniferous. Mr. WACHSMUTH'S collec- 

 lectiou. 



ERISOCRINUS WHITEI, M. and W. 



PI. 2, Fig. 2. 

 Erisocrinus Whitei, MEEK and WOETHEN. Proceed. Acad. Nat. Sci., Pliila., 1869, p. 72, 



BODY of moderate size, very much depressed, or almost 

 dish-shaped below the top of the first radials, being about 

 three times as wide as high. Base very small, and entirely 

 hidden by the slender, round column, when it is attached. 

 Subradials forming together a nearly flat, pentagonal disc. 

 First radials comparatively large, thick, and presenting a 

 general quadrangular outline, there being scarcely any 

 visible angle at the middle of the under side, which is dis- 

 tinctly shorter than the straight, transverse upper edge, 

 and about as long as the diverging lateral margins. Sec- 

 ond radial pieces as large as the first, which they equal in 

 breadth, broadly rounded on the outer or dorsal side, pen- 

 tagonal in form, and each supporting on its superior slop- 

 ing sides two arms, thus making ten to the whole series. 

 Arms simple from their origin, flat on the outside, and com- 



