272 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 



ently of all arm plates^ are covered with well marked radiating strise and 

 grooves. The arms in their free state branch but once; they are rather thin, 

 especially at the upper ends, and composed of short, somewhat cuneate 

 pieces. Interradial spaces slightly impressed between the costals, and dis- 

 tinctly grooved between the distichals. First interbrachials about as large 

 as the radials; the plates of the second row a little smaller, supporting 

 a fourth plate between their upper sloping faces, and two plates in the next 

 two rows, followed by numerous small pieces, which enclose the fixed pin- 

 nules. The anal area is a little wider, having three plates in the second and 

 all succeeding rows up to the first pinnule -, the middle series being marked 

 by a rather conspicuous ridge. Interdistichal spaces elongate, their median 

 portions deeply grooved ; the first plate large, followed by two plates in the 

 second row, and a number of small pieces above. Construction of the ventral 

 disk, and position of tlie anus unknown. Column round, — not indistinctly 

 pentangular as stated by Meek; the nodal joints somewhat larger; the axial 

 canal pentalobate, and moderately large. 



Horizon and Locality. — Hudson River group ; at Cincinnati, Lebanon and 

 Waynesville, Ohio, and also found at Richmond, Ind. 



Ti/pe in the Museum of Comparative Zoology, Cambridge. 



Remarks. — This species is readily distinguished from G. decadadylus, its 

 nearest ally, by the uninterrupted series of anal plates. It is quite remark- 

 able for its large number of incorporated pinnules, of which the proximal 

 ones have almost the proportions of armlets. Meek's G. Byeri, var. globosus, 

 which we thought to be a good-species, judging from the figures, can hardly 

 rank even as a variety. We have examined the type in the Museum of 

 Comparative Zoology, and find it to have all the characteristics of G. Byeti. 

 Wetherby's G. Richardsoni also, which we once regarded as a Reteocrinus, is 

 based upon a somewhat aberrant specimen of this species. 



(?) Glyptocrinus Shafferi Miller. 

 Plate XXI. Figs. Sd, ej. 



1875. Glyptocrinus Shafferi — ^. A. Millek; Cincin. Quarterly Journ. Sci., Vol. IL, p. 277; and 1880, 

 Journ. Cincin. Soc. Nat. Hist., Vol. III., p. 233, Plate 7, Kgs. 2«, b, and 3^, b, c. 



1881. Qlyptocrinus Shafferi — W. and Sp. ; Revision Paleeocr., Part IL, p. 189. 



1883. Pycnocrinus Shafferi—^. A. Miller; Journ. Cincin. Soc. Nat. Hist., Vol. VI., p. 231, and North 

 Amer. Geol. and Palseont., p. 276. 



There is but little doubt that the small specimens which S. A. Miller 

 described as Glyptocrinus Shafferi, and G. Shafferi, var. germanus, and for 



