RHIPIDOCRINUS. 203 



2. Genus. — Rhipidocrinus, Zittel, 1876. 



This genus " differs very materially in tbe arm-structure from Rhodocrinus as 

 established by Miller" (Wachsmuth and Springer). 



1. Rhipidocrinos crenatus, Goldfuss, sp. ? Plate XXIII, figs. 8, 8 a. 



1827. Ehodocrinites crenatus, Goldfuss. Petref. Germ., vol. i, p. 211, 



pi. lxiv, fig. 3. 

 1835. — Agassiz. Mem. Soc. Neufchatel, vol. i, p. 196. 



1851. Ehodocrinus crenatus, F. Bbmer. Verb. Nat. Vereins Eheinl., vol. viii, 



p. 358, pi. i, fig. 1. 

 1853. — tessellatus, Steininger. Geogn. Besch. Eifel., p. 36. 



1855. — F. Burner. In Bronn's Lethsea Geogn., edit. 3, 



vol. i, p. 241, pi. iv. figs. 17 a, b. 

 1867. crenatus, Schultze. Denksch. Kais. Akad. Wissensch., 



vol. xxvi, p. 165, pi. vii, fig. 1. 

 1876. — — F. Bomer. Letbsea Pal., pi. xxvii, fig. 14. 



1880. Ehipidocrinus crenatus, Zittel. Handbuch Palseont., p. 377, fig. 263. 



1881. Eipidocrinus crenatus, Wachsmuth and Springer. Proc. Acad. N. S. 



Philad. p. 379. 

 1889. Ehodocrinus crenatus ?, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 79. 



Description. — Calyx of moderate size, oblately spheroidal, with concave base. 

 Attachment of column large, circular, with radiating stria?. Basals ? Radials and 

 primibrachs 3 X5? transverse. Secundibrachs 2 X 10? Interambulacrals hexa- 

 gonal, first row 5, medial between the radials and the first primibrachs ; second 

 row 10, smaller. Surface of plates convex, structure very massive. Tegmen 

 constricted, flatfish. 



Size of calyx. — Height about 20 mm., width 45 mm. 



Locality. — One worn specimen from Lummaton is in my Collection, and another, 

 probably from the same locality, in the Torqua}^ Museum. 



Remarks. — These specimens are so badly preserved as to be almost unde- 

 cipherable ; in one the plates are entirely obliterated, and in the other they can 

 only be traced approximately. The general shape of the calyx, however, is evident, 

 and is totally unlike any other South Devon crinoid. Mr. Bather agrees with me 

 that they probably belong to Rhodocrinus crenatus, Goldfuss, though the basals are 

 very much smaller than usual in this species, so small indeed as to be unobservable 

 in these specimens. 



