394 THE CRINOIDEA CAMEEATA OF NORTH AMERICA. 



in the lower portions, flattened and broader above, increasing gradually to 

 three times their width at the base. They are composed of a double series 

 of short pieces, and are provided along their outer sides with small nodes, 

 ■which in the flattened portions turn into short spines. Near the calyx every 

 plate is spine-bearing, but higher up only each second or third. Regular 

 interbrachials from two to four, arranged in the usual way, the anal side has 

 three in the first, and two or three in the second row ; the anal plate gen- 

 erally a little smaller than the radials. The ventral disk is composed of 

 slightly nodose plates, its anterior side higher than the posterior, the pos- 

 terior oral prominent. Anal tube subcentral and slender. Column rather 

 stout, the nodal joints considerably wider and longer than the intervening 

 ones, and angular at their edges. 



Horizon and Lomlitij. — Lower Burlington limestone ; Burlington, Iowa. 



Types in the University Museum at Ann Arbor, and in the collection of 

 Wachsmuth and Springer. 



Eretmocrinus neglectus Meek and Woethen. 

 Plate XXXVI. Fig. 3. 



1868. Batomiius (Erelmomxiis) neglectus — Meek aad Wouthen ; Proc. Acad. Nat. Sci. Pljila., p. 355. 

 1873. Batocriims {Eretmocrinus r) neglectus — M. and W. ; Geol Kep. Illinois, Vol. V., p. 377, Plate 5, 



Figs. 3a, b. 

 1877. Batocriims neglectus — S. A. Millek ; Amer. Palaeoz. Foss., p. 72. 

 1831. Bretmocriiius neglectus — W. and Sp. ; Revision PalaBOcr., Part II., p. 173. 

 1890. Bretmocrinus neglectus — S. A. Millee ; North Amer. Geol. and Palseont., p. 243. 



Of the type of E. dio. Calyx higher than wide ; the dorsal cup inversely 

 campanulate ; the sides expanding gradually from the base to the distichals, 

 thence curving more rapidly to the upper edges of the arm-bearing plates, 

 which are slightly grooved but in contact all around ; the plates regularly 

 convex, especially the radials, first interbrachials, and the anal plate. 



Radials comparatively large, almost as long as wide. First costals quad- 

 rangular, a little wider than long ; the second frequently heptangular, wider 

 than the first but not longer. Distichals one, large, axillary ; supporting two 

 short palmars and four arms in each ray, unless the anterior ray, which is 

 quite often the case, has but two arms, when the large distichal is followed 

 by two smaller. Arm facets small, facing outward. Respiratory pores almost 

 as large as the ambulacral openings ; they occupy the lower end of narrow, 

 well defined longitudinal grooves, which extend up into the tegmen for quite 

 a distance. Arm structure unknown. Interbrachials generally three, except 



