No. 189.J 59 



obtusely wedgeform above, and supporting an arm on each 

 sloping face. 



Arms bifurcating on the sixth, eighth or tenth plate, and some- 

 times on the fourteenth plate from their base ; each of the 

 divisions again bifurcating. Arm -plates supporting jointed 

 angular tentacula. Anal plates unknown, 



Plates of the body angular in the middle, with short angular 

 ridges running from the centre of the subradials to the basal 

 plates, and also to the first radial plates. The second radial 

 plate, as well as all the plates of the arms, are longitudinally 

 angulated or carinate in the middle. The carination follows 

 the enlargement of the arm -joint towards the origin of the 

 tentacula, giving a somewhat tortuous direction to the arm. 



Entire surface minutely granulose, or sometimes striato-granulose. 



Column subpentangular, and composed of very unequal joints. 



This species closely resembles Scaphiocrinus carinatus of the Burlington lime- 

 stone, but differs in the bifurcation of the arms, and more materially in having but 

 two radial plates in the series, while that one has three. 



SCAPHIOCRINUS SUBTORTUOSUS (n.s.). 



Body small, cyathiform. Basal plates minute : subradial plates 

 about as long as wide. First radial plates much wider than long, 

 the second and third plates very short ; the latter obtusely 

 wedgeform above, and supporting two arms, which again bi- 

 furcate on the ninth and twelfth plates from the third radial. 

 No other bifurcations of the arms have been determined. Anal 

 plates unknown. 



The plates of the body are very prominent in the middle, with 

 strong angular ridges extending to the margins, and joining 

 those of the adjacent plates. Plates of the arms constricted in 

 the middle, and longitudinally subangular. 



In the structure of the calyx, form and character of the plates, it resembles the 

 S. tortuosus of the Burlington limestone; but in the structure of its arms, and the 

 existence of three radial plates in the series, it more nearly resembles the S. cari- 

 natus of the same limestone. 



GENUS ZEACRINUS ( Troost). 



ZEACRINUS PATERNUS (n.s.). 



Body small : calyx flattened or broadly cyathiform. Basal plates 

 very small, concealed within the cavity of the column : sub- 

 radials of moderate size, wider than high, their lower margins 

 curving into the basal depression ; first radials as wide again 

 as high, concave on their upper margins. Second radials, in the 

 antero- lateral and postero -lateral rays, subequal or a little 

 wider than high, obtusely wedgeform above, and supporting an 

 arm on each sloping face ; each of which, in the antero-lateral 

 rays, again bifurcates on the eighth or tenth plate above their 



