284 THE CEmOIDEA CAMEEATA OF NOETH AMEEICA. 



sloping upper faces of two radials. Neither is anything known of the con- 

 struction of the disk. Column round, of moderate size, slightly tapering 

 downwards- near the calyx the nodal joints are somewhat larger than the 

 internodal ones, but at a length of about three inches all joints are of nearly 

 equal size. 



Horizon and Locality. — Niagara shale ; Lockport, N. Y. 



Type in the collection of Dr. Eugene Ringueberg, Lockport. 



Mariacrinus plumosus* Hall. 

 Plate XXIIL Figs. 6 and 7. 



1859. Hall; Palj»ont. New York, Vol. HI., p. 110, Plate 3, Figs. 6-11. 

 1881. W. and Sp. ; Revision Paleeocr. Part XL, p. 116. 



A small species. Dorsal cup apparently obconical; the surface orna- 

 mented by strong radiating ridges, proceeding from the centre of the plates 

 to adjoining ones. Basals about as long as wide. Eadials a little longer 

 than wide. Costals nearly as large as the radials and of similar form. Dis- 

 tichals 3 X 10, each row supporting two arms, twenty in all. Arms simple, 

 rather long, composed of slightly cuneate joints. In the two outer arms, the 

 second joint gives off a pinnule to the outer side, the third is a hypozygal 

 joint, and the fourth gives off the second pinnule at the inner side; all suc- 

 ceeding joints being pinnule-bearing. The two inner arms, according to 

 Hall, support no pinnules up to the eighth joint, but this needs confirmation. 

 Interbrachials, 1, 2, 2, 2. The arrangement of plates in the anal interradius 

 and construction of the ventral disk unknown. Column round, compara- 

 tively large. 



Horizon and Locality. — In the shaly layers of the Pentamerous limestone, 

 Wheelock's Hill, Litchfield, Herkimer Co., N. Y. 



(?) Mariacrinus ramosus^ Hall. 



1859. Hall ; Palseont. New York, Vol. III., p. 147, Plate 2, Pig. 6. 

 1881. W. and Sp.; Revision Palgeocr., Part II., p. 116. 



Dorsal cup urn-shaped, the rays marked by strong ridges, which pass into 

 the arras. Basals small. Eadials and costals higher than wide. Distichals 



* We are somewhat in doubt as to tlie generic relations of this species, and think it possible from Hall's 

 figure that it may possess infiabasals, and therefore belong to a different genus. We do not reproduce the 

 original figure, because it does not agree with the description, either in the arrangement of the plates in the 

 calyx, or the construction of the arms. We had no opportunity to see the type specimen, and only can give 

 an abstract of Hall's description. 



