BATOCRINIDjE. 375 



kry distichal supports 2X4 palmars. The arm-bearing plates are very 

 prominent, being separated by deep notches, which give to the rim, as seen 

 in a dorsal or ventral aspect, a strongly dentate outline. Arm openings 

 almost equidistant, directed upward. Arms eighteen, their structure not 

 known. Interbrachials three ; the first large, a little wider than long, the 

 two upper ones small. Anal plate somewhat narrower than the radials, fol- 

 lowed by three plates, of which the middle one is considerably the largest, 

 and these apparently by three smaller ones. Disk nearly as high as the 

 dorsal cup, the sides but very shghtly convex ; composed of moderately 

 large, conical plates, among which the orals are readily recognized by their 

 larger size. Anal tube almost central and of moderate size. 



Honzon and Locality. — Base of the Lower Burlington limestone ; 

 Louisiana, Mo. 



TyTpes in the collection of Prof. Rowley. 



Remarks. — We regard this species as representing a transition toward 

 Lobocrinus and Eretmocriniis, and we should not be surprised if it had paddle- 

 shaped arms. It resembles in general form Lobocrinus (Equihrachiattis, espe- 

 cially the larger specimens, in which the arms show a tendency to grouping 

 into pairs ; but the interbrachials are arched by the palmars — or distichals at 

 the anterior side — and consist of but three plates. The species should also 

 be compared with Eretmocrinus clio Hall. 



Batocrinus turbinatus (Hall). 

 Plate XXVIL Figs. 5a, h, c. 



1838. Aetimermus turbiiialiis — Hall ; Geol. Rep. Iowa, Vol. I., Part II., p. 587, Plate 11, Fig. 1. 

 1873. Batocrinus turbinatus — Meek and Worthen ; Geol. Rep. Illinois, Vol. V., p. 367. 

 1881. Batocrinus turbinatus — W. aud Sp. ; Revision Palseocr., Part II., p. 168. 



Sjn. Batocrinus Itstus Millee and Gurlet, 189i ; Geol. Saw. Illinois, Bull. 3, p. 24, Plate 5, Pigs. 

 10, 11, 12. 



Calyx to the base of the anal tube generally as wide as high; the dorsal 

 cup one third higher than the ventral disk. Sides but very little concave, 

 straight from the bottom of the basals to the plates supporting the free 

 arms ; the latter plates projecting. Plates throughout the dorsal cup almost 

 flat, their surfaces smooth ; the suture lines indistinctly grooved. 



Basal cup somewhat obconical, sometimes slightly thickened ; lower face 

 concave and projecting over the column. Radials large, once and a half as 

 wide as long, the upper face distinctly concave. First costals transversely 



