456 THE CRINOIDEA CAMEEATA OF NORTH AMERICA. 



arm bases. First anal plate longer than the radials, the median portions 

 marked by a transverse ridge, followed by a longitudinal row of four 

 additional anals, and these by a moderate number of irregular pieces which 

 surround the anus. The four latter anals sustain at their sides a row of 

 elongate plates, which decrease in size upwards. Anal area elevated, the 

 median line forming a rounded ridge, which passes up to the posterior 

 oral. Ventral disk inflated, as high as the dorsal cup, pentagonal in out- 

 line. The spines are long, sometimes reaching a length of 5 cm. or more ; 

 the other plates of the disk flat, or moderately convex. The posterior oral, 

 which is represented by the central spine, is as large at its base as the other 

 four orals together ; tlie latter are pushed anteriorly. The first radial dome 

 plates, which are represented by the five lateral spines are surrounded by 

 five rather large plates, and these are followed downward by two secondary 

 radial pieces and a large interambulacral. Anus on a level with the lateral 

 spines, the opening directed laterally. 



Horizon and Locality. — Upper part of the Keokuk group ; Keokuk, 

 Iowa, and Warsaw, Hamilton, and Nauvoo, Ills., also found at White's 

 creek near Nashville, Tenn., and at several localities in Indiana and 

 Kentucky. 



Types in the Mineralogical Museum at Breslau, Germany. 



BemarJcs. — Since the above descrij)tion was written, we have examined 

 a fine specimen in the collection of L. A. Cox of Keokuk, in which the arms 

 are preserved to near their full length, and 13 cm. of the stem. The arms 

 are paired and of moderate size ; they are composed of rather long joints, 

 which are not spine-bearing so far as observed. The column is rather heavy 

 at the top, but tapers gradually from 8 mm. to 4 at the lower end. The 

 first internodal joint exposed to view occurs between the eighth and ninth 

 joints, but they increase rapidly in number, and soon attain the form and 

 size of the nodal joints, which gradually become cylindrical and narrower. 



Dorycrinus Gouldi (Hall). 

 Plate XLIII. Figs. B, S, and Plate XLIY. Figs. 4, 5. 



ISoS. Jctimcnnm Gouldi — 'Raja.; Geol. Eep. Iowa, "Vol. I., Part II., p. 613, Plate 15, Tigs. 6ff, b, c. 

 1873. Sori/crinas Gouldi — Meek and Woethes ; Geol. Rep. Illinois, Vol. V., p. 380. 

 18S1. Dori/criims Gouldi— yf. and Sp. ; Revision Palffiocr., Part 11., p. 179 (Proceed. Aead. Nat. Sci. 

 Pliila., p. 353). 



Cah'x about as high as wide, crowned by six extravagantly developed 

 spines. Dorsal cup obpyramidal, obscurely pentangular to the top of the 



