n4 



POTERIOClllNUS LAliVKlNTimni.S, S. A. Miller. 



Flaie I V, Fig. 7, azygons view. 



{CyrilhorrinHS hthi/riulhicus, S. A. Miller, 1891. Advanco 

 sheets of the 17th ivpoi-t of the Geology and Natural History 

 of Indiana, page 4>^. and final rei)ort, page 6r)9, plate XII, figs. 

 11 to M.] 



Though several specimens of this species had been collect(>d 

 at the lime it was' desc]'il)ed, none of them fully exposed the 

 azygons area. They showed the azygous jdatc truncating a 

 large subradial but the folding of the arms around the calyx 

 happened to cover the first azygous plate, which rests between 

 the suj)erior sloping sides of two subradials, and separates the 

 first radial on the right from the second azygous j)late and is 

 truncated above by the third azygous j)]ato, which shows that 

 it is a I'<>len'ocriiii(<!. 'Vha second plate is large and broadly 

 truncates a subiadial and was supposed at the time of the 

 description of the species to be the first azygous plate which 

 caused the sjiecies to be erroneously i-eferred to Ci/alhocrhnis. 

 The position of the first and second azygous plates and the 

 alternate arrangenient of tlie succeeding plates show very 

 clearly that it is a Poierlocrinus?. 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 exposui-e of the 

 Keokuk (ironp, at- Hoonville, Missoui'i, and is now in the col- 

 lection of Wm. F. E. Ciurley. 



scAi'inocuiNrs notatts, n. sp. 



PIdle If, Fig. 2~i, ozijgoii.s vieir: Fig. W, opposife si<lf of same 

 S2>ecime7i, tohich is slighily eom pressed. 



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, dc- 

 ])rcssed angular between the first and st^cond radials, so as to 

 give a pentagonal outline. 



Column small, round, although broken away from the specimen 

 figured and the small basal ])lates have been carried away with it, 

 as the angles between t he plates shown in fig. iT) indicate. Subradi- 

 als evidently larger than the ba.sals, four hexagonal andonehep- 

 tagonal. The lateral sides gradiially ex])and. First radials nearly 



