SPfLEROCRINUS. 211 



1. Sph^rocrinus geometricus, Goldfuss, sp. Plate XXIV, figs. 7—10. 



1826-34. Ctathocrinus geometricus, Goldfuss. Petref. Germ., vol. i, p. 189, 



pi. lviii, fig. 5. 

 1841. Phillips. Pal. Foss., p. 135, pi. lx, fig. -41*. 



1843. — — Austin. Recent and Fossil Criuoids, 



p. Gl, pi. vii, figs. 5 a — e. 

 1851. SpHiEROCRiNUs geometricus, F. Homer. Verb. Nat. Vereins Rheinl., 



vol. viii, p. 366, pi. viii, fig. 1. 

 1853. steelatus (Schnur), Steininger. Geogn. Bescb. Eifel, 



p. 38. 

 1855. geometricus, Sandberger. Verst. Kbein. Nassau, p. 390, 



pi. xxxv, fig. 14. 



1855. sp., F. A. Miner. Beitr. Harz., pt. 3, p. 22, pi. iv, fig. 15. 



1856. Poteriockinus tiEOMETRicus.iI/w//er. Abhandl. Berlin. Akad. Wissenscb., 



p. 250, pi. ii, figs. 4 — 7 ; and 

 pi. iv, fi^s. 1—3. 

 185b*. jiemisph^ericus, Midler. Monats. Berlin. Akad. Wissenscb., 



p. 354. 

 1867. — geometricus, Schultze. Denkscb. Akad. Wissenscb. Wien, 



vol. xxvi, p. 163, pi. v, figs. 6 a — I. 

 L879. Ctathocrinus geometricu s, Waclismutli and Springer. Proc. Acad. N. S. 



Philad., p. 308. 

 1886. Sph^erockinus ? geometricus, Wachsmuth and Springer. Ibid., p. 150. 

 1892. Parisocrinus ? geometricus, Bather. Ann. Mag. Nat. Hist., ser. G 



vol. ix, p. 20s. 



Description. — Calyx sometimes very large, usually rather small, short, oblately 

 spheroidal. Attachment of column rather large. Infra-basal circlet large, penta- 

 gonal, consisting of five lozenge-shaped (or pentagonal by the truncation of 

 their proximal margins) plates, which are rather longer than wide. Basals five, 

 hexagonal, wider than long, large. Radials five, rather small, unequal, incurved. 

 Anal area containing a radianal, an anal X , and another small plate on the right 

 of anal X , and resting on the radianal. Arms five, erect. Ventral side contracted. 

 Ornament consisting of parallel, elevated, radiating ridges, starting from the 

 centres of the infra-basal circlet, and of the basal plates, and from the insertion of 

 the arms, so as to form a curious geometric pattern over the whole calyx. 



Size. — An imperfect calyx measures from the arms to base 30 mm, width 

 45 mm. Another perfect specimen measures 20 mm. in height, and 30 mm. in 

 width. 



Localities. — From Wolborough there are eight specimens in the Museum of 

 Practical Geology, two in Mr. Vicary's Collection, two in the Torquay Museum, 

 and two in my Collection. From Lummaton there is a cast in my Collection. 



