34 



POTERIOCR1NUS LAB YUINTH1CUS, S. A. Miller. 



Plate IV, Fig. 7, azygous view. 

 [Cyalhocriniis labyrinthicus, S. A. Miller, .1891. Advance 

 sheets of the 17th report of the Geology and Natural History 

 of Indiana, page 48, and final report, page 659, plate XII, figs. 

 11 to 14.] 



Though several specimens of this species had been collected 

 at the time it was- described, none of them fully exposed the 

 azygous area. They showed the azygous plate truncating a 

 large subradial but the folding of the arms around the calyx 

 happened to cover the first azygous plate, which rests between 

 the superior sloping sides of two subradials, and separates the 

 first radial on the right from the second azygous plate and is 

 truncated above by the third azygous plate, which shows that 

 it is a Poteriocrinus. The second plate is large and broadly 

 truncates a subradial and was supposed at the time of the 

 description of the species to be the first azygous plate which 

 caused the species to be erroneously referred to Cyathocrinus. 

 The position of the first and second azygous plates and the 

 alternate arrangement of the succeeding plates show very 

 clearly that it is a Poteriocrinus. Several specimens showing 

 this fact are in the collection of S. A. Miller, but received by 

 him after the species had been described and illustrated. The 

 specimen now illustrated is from the same exposure of the 

 Keokuk Group, at Boonville, Missouri, and is now in the col- 

 lection of Wm. F. E. Gurley. 



SCAPHIOCRINUS NOTATUS, n. Sp. 



Plate II, Fig. 25, azygous view; Fig. 26, opposite side of same 

 specimen, which is slightly- compressed. 



The specimen illustrated is compressed so as to appear 

 about one- fifth wider than it really is. The species is above 

 medium size. Calyx short, about twice as wide as high, de- 

 pressed angular between the first and second radials, so as to 

 give a pentagonal outline. 



Column small, round, although broken away from the specimen 

 figured and the small basal plates have been carried away with it, 

 as the angles between the plates shown in fig. 25 indicate. Subradi- 

 als evidently larger than the basals, four hexagonal and onehep- 

 tagonal. The lateral sides gradually expand. First radials nearly 



