26 PROCEEDINGS OF THE AMERICAN ACADEMY 



Geological position and locality. A single specimen of the calyx 

 was obtained from the first limestone above tlie base of the millstone- 

 grit beds, in Hardin County, Kentucky. 



Remarks. The ornature of this beautiful crinoid will distinguish 

 this from all other known species. 



COTYLEDONOCRINUS, Nov. Gen. 



Generic formula : — 



Basal pieces, . . 2. 



Eadial pieces, . . 3x5; first large and long ; 



second minute ; third small, axillary. 

 Secondary radial pieces, 2 X 10. 

 Arms, . . . . 10 ; long, ciliated. 

 Inter-radial pieces, . 3x5; small. 

 Mouth subcentral. 



Summit covered by many j^olymorphous pieces. 

 Column round, small, formed of alternate large and small 



thin pieces. 

 Radial pieces all arm-bearing. 

 Anal piece none. 



COTYLEDONOCRIXUS PENTALOBDS, Sp. Nov. 



Body. When the arms are absent the body is a long ovoid figure ; 

 the summit contracting rapidly, while the lower portion of the calyx, 

 as high as the top of the basal pieces, is rather more elongated. 

 The base is rounded, and intumescent about the column. The two 

 hasal pieces, when united, form a conical cup about as deep as wide, 

 having four slight concave depressions on its upper margin, and one 

 angular notch. The junction of the basals rises between the concave 

 depressions, dividing them into pairs, the angular notch being equally 

 taken from the pieces on either side of the line dividing them. Co- 

 lumnar pit small, the presence of the column in our specimens con- 

 cealing its depth ; it is probably quite shallow. 



The Jirst primary radials are large, more than twice as high as 

 wide, a httle wider in the middle of the length of the pieces than at 

 the ends. The second and third primary radials are burfed in an 

 excavation at the summit of the first radials. There is no gibbosity 

 or swelling at the insertion of the second radials; the fii'st radials 

 appear to run under them perfectly smooth. 



