1881.] NATURAL SCIENCES OP PHILADELPHIA. 383 



There is properly only a single plate in each interradial area, 

 and this, as stated, rests upon the truncate upper side of the 

 basals between both primary radials, and extends to the arm 

 bases. It is the largest plate of the entire calyx, hexagonal, 

 higher than wide, and supports upon its upper side — between 

 the arms — the interbrachial plates above mentioned. The anal 

 area, if we interpret Angelin's figure correctly, differs in having 

 above its first plate a row of smaller plates, longitudinally 

 arranged as in Glyptaster and Eucrinus, and these support the 

 anus. 



Vault and anal aperture unknown. Column round. 

 Geological Position^ etc. — The two known species are from the 

 Upper Silurian of Sweden. 



* Anthemoorinus minor Angelin. (Eucr, minor) Icon. Crin. Suec, p. 25, PI. 15, 



fig. 5, Upper Silurian. iJothland, Sweden. 

 . * Anthemocr. venustus Angelin. Type of the genus fEucr. venustus\ Ic^n. 

 Crin. Suec, p. 25, PI. 15, figs. 7, 16. Upper Silurian. Gothland, Sweden. 



12. EHODOCRINtrS Miller. 



1821. Miller. Natur. Hist, of the Crinoidea, p. 106. 



1835. Agassiz. Mem. Soc. Sci., Neuchat,, i, p. 196. 



1841. Miiller. Monatsb. Berl. Akad., i, p. 209. 



1843. Austin. Ann. and Mag. Nat. Hist., i, p. 109. 



1850. D'Orbigny. Prodr. de Paleont, i, p. 1C4. 



1853. De Koninck and Lelion. Recher. Crin. Carb. Belg., p. 103, 



1855. Roemer. Lethaea Geogn. (Avisg. 3), p. 240. 



1855. Wirtgen and Zeiler. Verb. Naturh. Verein f. RheinL, xii, p. 11. 



1858. Hall. Geol. Rep. Iowa, i, pt. ii, p. 556. 



1861. Hall. Bost. .Journ. Nat. Hist., p. 322. 



1879. Zittel. Handb. der Palaeont, i, p. 376 



{'Sot Bhodoerinm Goldf. 1826, Petref. Germ, i, p. 312 ; nor Billings, 

 1859, Geol. Rep. Canada, Decade iv, p. 61 ; nor Schultze, 1867, 

 Echin, Eifl. Kalk, p. 53 ; nor Roemer, 1851, Verb. Naturh. 

 Verein f. Rheinl., viii, p. 358), 

 Syn. Acanthocrinus F. Roemer. 1850, Neues Jahrb. f. Mineralogie 

 p. 79 ; Miiller (Wirtgen and Zeiler) 1855, Verh. Naturh. Verein, 

 xii, p. 8 ; Pictet, 1857, Traite de Paleont, iv, p. 100, Hall, 1862, 

 (subgenus of Bhodocrinus) 15th Rep. N. T. St. Cab. Nat. Hist., 

 p. 125. 



Rliodocrinus verus, according to Miller, occurs in both the 

 Mountain limestone and in the Upper Silurian, and it was said to 

 have three basal plates. As we have before shown, Miller con- 



