TKOOST'S CRINOIDS OF TENNESSEE E. WOOD. 



49 



It is entirely siliceous. The smallest marks on the ringers and the summit have 

 been preserved during fossilification. They are not at all mutilated, but no feathers 

 or tentacula [pinnules] on the fingers are perceptible. 



The single specimen of Eucalyptocrinites tennesseese in the Troost 

 collection is indistinguishable from E. ovalis. Troost's description of 

 E. tennesseese is as follows : 



The body of this species is hemispherical and its surface is smooth. The cavity for 

 the insertion of the column is circular and in proportion much larger than that of the 

 E. splendidus with which it has some resemblance. The fingers are externally round 

 and do not project beyond the general level, as is the case with the E. splendidus. It 

 can not be a juvenile of the latter; I possess a juvenile cup of it which is in every 

 respect similar to the adult — it is inverted conical and corrugate, and not hemispher- 

 ical and smooth like the E. tennessee. 



Observations. — Eucalyptocrinus ovalis is characterized by the regu- 

 larly oval outline of the body, small circular basal excavation, and 

 smooth surface. 



Formation and locality. — Brownsport limestone. Decatur and 

 Perry counties, Tennessee; Waldron and Hartsville, Indiana. 

 Cat. Nos. 39952, 39954, 39960, U.S.N.M. 



EUCALYPTOCRINUS EXTENSUS Troost. 



Plate 13, figs. 9, 10. 



Eucalyptocrinites extensus Troost, Proc. Amer. Ass. Adv. Sci., II (read 1849), 



1850, p. 60 (nomen nudum); MSS., 1850. 

 Eucalyptocrinus extensus Shumard, Trans. Acad. Sci. St. Louis, II, 1866, p. 370 



(catalogue name). — Wachsmuth and Springer, Rev. Palseocrinoidea, III, 



1885, p. 128 (catalogue name). — Miller, North Amer. Geol. and Pal., 1889, 



p. 244 (catalogue name). 



The description by Troost is as follows: 



The cup is low basin shaped. The cavity for the column pentagonal, not very 

 large — the plates tumid. 



Supplementary description. — Only the calyx of this species is pre- 

 served. Its height to the level of the arm bases is 20 mm. and its 

 greatest diameter 34 mm. The cup is distinctly flattened in the 

 region of the first primibrachs, which causes the outline of the sides to 

 be concave below and convex above. The body is also very slightly 

 flattened in the region of the intersecundibrachs and the second inter- 

 brachials. The plates are slightly convex, with sutures distinctly 

 visible but not beveled. 



In one ray the first interbrachial is wanting, an abnormal feature 

 of frequent occurrence among Crinoidea. 



Surface smooth. 



The basal excavation is but little larger than the column and dis- 

 tinctly pentagonal, with the angles of the pentagon directed radially. 



Observations. — This species resembles E. turbinatus in form and 

 size but differs in its convex instead of concave plates and in the 

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