318 PROCEEDINGS OF THE ACADEMY OF [1885. 



agrees with Reteocrinus and Canistrocrinus, to which we refer 

 for further particulars. We place in this genus also " Glyptocri- 

 nus" Baeri Meek, which we have heretofore referred to Reteocri- 

 nus, not knowing the construction of its basal portions. It has 

 not only four basals, but fundamentally a quadrangular column, 

 the more or less cylindrical outline being caused by knife-like lat- 

 eral extensions along the joints ; its cross-section shows the nu- 

 cleus to be strictly quadrangular. 



Geological Position, etc. — Hudson River group of the Ohio 

 valley. 



*1S72. Xenocrinus Baeri (Meek). Glyptocrinus Baeri, Amer. Journ. Sci. iii (Ser. 3), 

 p. 260; also IS;:;. Geo!. Rep. Ohio, Paleont. I, p. 37, PI. 2, fig. 1 a, b.— S. 

 A. Miller, 1880, Journ. Cincin. Soc. Nat. Hist., vol. iii, PI. 7. fig. 4.— Reteo- 

 crinus Baeri W. & Sp., 1881, Revision ii, p. 193; also Arner. Journ. Sci., vol. 

 x.w, p. I't'iO.— Glyptocr. Baeri S. A. Miller, 1883, Journ. Ciueiu. Soc. Nat. 

 llist., vol. vi, p. 226.— Hudson River gr., Ohio valley. 



1881. Xenocrinus penicillus S. A. Miller. Type of the genus. Journ. Cincin. Soc. 

 Nat. Hist., vol. iv (April), PI. I, fig. 3, and ibid. July), PI. 4, fig. 6.— Hudson 

 River gr. Wayuesville, 0. 



Family IT.— RHODOCRINIDJE Roemer. 



(Emend., Zittel ; emend., W. and Sp.) 



ARCHJEOCRINUS W. and Sp. 



1881. W. and Sp. Revision, ii, p. 189. 



1883. S. A. Miller. Journ. Cincin. Soc. Nat. Hist., vol. vi, p. 217. 



Syn. Lyriocrinus (S. A. Miller not Hall), 1882, Journ. Cincin. Soc. 

 Nat. Hist, vol. v. 



Mr. Walter R. Billings informs us that all the species which 

 we referred to Archseocrinus, possess a special anal piece placed 

 between the interradials of the second series. In Part II, p. 190, 

 we erroneously stated that the anal interradius could not be dis- 

 tinguished from the four others, and we are obliged to Mr. Bil- 

 lings for making this correction. We find it confirmed by some 

 interesting specimens which we recentlj- collected from the Tren- 

 ton limestone near Knoxville, Tenn. Most of these specimens 

 represent Miller's " Lyriocrinus " sculptus, which was supposed 

 to come from the Niagara group, but which evidently came from 

 a lower horizon. Our specimens were found associated with By- 

 bocrinus and other characteristic Lower Silurian fossils. Lyrio- 

 crinus sculptus Miller, or, as we call it, Archeeocrinus sculptus, is 



