TROOST 's CRINOIDS OF TENNESSEE — E. WOOD. 



13 



on the left bank of the Tennessee River. I found in the Silurian strata only one 

 species, the P. reinwardtii, which is very distinct from all other species of Tennessee 

 Pentremites. 



PENTREMITES GODONI (Defiance). 



Plate 3, fig. 5. 



Kentucky Asterial Fossil Parkinson, Org. Rem. of a former World, 1808, p. 235, 



pi. xiii, figs. 36, 37. 

 Encrina godoni Defrance, Diet. Sci. Nat., XIV, 1819, p. 467. 

 Pentremites globosa Christy, Letters on Geol., 1848, pi. iv, figs. 7, 8. 

 Pentremites globosus Troost, MSS., 1850. 



Pentremites godoni Shumard, Trans. Acad. Sci. St. Louis, I, 1858, p. 245. — Hall, 

 Rep. Geol. Surv. Iowa, I, Pt. 2, 1858, p. 692, pi. xxv, figs. 13 a, b. — Shumard, 

 z Trans. Acad. Sci. St. Louis, II, 1866, p. 384 (catalogue name). — Billings, 



Amer. Journ. Sci., XLVIII, 1869, p. 81, fig. 13.— White, 2nd Ann. Rep. 

 Dep. Stat, and Geol. Indiana, 1881, p. 511, pi. vn, figs. 10, 11. — Etheridge and 

 Carpenter, Cat. Blastoidea, 1886, p. 157, pi. i, fig. 11; pi. n, figs. 1-13; 

 pi. xii, tigs. 16-17; pi. xvi, figs. 19, 22, 23. — Miller, North Amer. Geol. and 

 Pal., 1889, p. 268 (catalogue name). — Keyes, Missouri Geol. Surv., IV, 1894, p. 

 136.— Weller, Bull. No. 153, U. S. Geol. Surv., 1898, p. 414 (catalogue 

 name). — Bather, List Blastoidea Brit. Mus. (Nat. Hist.), 1899, p. 45 (catalogue 

 name). — Hambach, Trans. Acad. Sci. St. Louis, XIII, 1903, p. 38, pi. m, 

 fig. 18. 



The following is Troost's description: 



Subspherical, vertically more or less flattened, base slightly pentagonal. Ambu- 

 lacra reaching to the base, fields of ambulacra slightly longitudinally curved, column 

 slender. 



Occurs (not abundant) near Sparta at the ascent of the Cumberland Mountain, 

 Craborchard Mountain in Bledsoe County, Tennessee; very abundant near Hunts- 

 ville, at Mount Sano, Alabama— Illinois and Kentucky. 



Observations. — This species has long been considered synonymous 

 with P. jlorealis, but Doctor Hambach separates the two species. 

 He says: 



Shumard and many later authors confound this species with Pentremites godoni, 

 which is a sad mistake because there is a considerable difference between these two 

 species. In the typical P. Jlorealis the body is more elongated, the base portion 

 drawn out and more prolonged than in Pentremites godoni, and the plications of the 

 ambulacral integument are coarser than in P. godoni. The typical Pentremites 

 Jlorealis is comparatively rare in Alabama and Kentucky but not so at Chester, Illinois,- 

 where Pentremites godoni does not occur at all. We find it again at Waterloo, Illinois, 

 associated with Pentremites Jlorealis, but it is by far the predominating species here. 



Cat. No. 33069, U.S.N.M. 



PENTREMITES PYRIFORMIS Say. 



Plate 2, figs. 13, 14, 15. 



Pentremites pyriformis Say, Journ. Acad. Nat. Sci. Phila., 1st. ser., IV, 1825, 

 p. 294; Zool. Journ., II, 1825, p. 314.— Troost, Trans. Geol. Soc. Pennsyl- 

 vania, I, Pt. 2, 1835, p. 228, pi. x, fig. 8. — Owen, Amer. Journ. Sci., 1st. 

 ser., XLIII, 1842, p. 20, fig. 3.— Christy, Letters on Geol., 1848, pi. iv, 

 fig. 6.— Troost, Proc. Amer. Ass. Adv. Sci., II (read 1849), 1850, p. 60 

 (catalogue name). — Hall, Rep. Geol. Surv. Iowa, I, Pt. 2, 1858, p. 693, 



