TROOST *S CRINOIDS OF TENNESSEE — E. WOOD. 



25 



plates are shown by the figures. The dorsal cup is thin at the base 

 but thickens rapidly upwards until the upper edge of the radials has 

 a thickness of one-fourth the greatest diameter of the cup. 



Formation and locality. — Found in the Knobs tone shale at Button- 

 mould Knob, 7 miles south of Louisville, Kentucky. 



Cat. No. 39911, U.S.N.M. 



Family HAPLOCRINIDiE Roemer. 

 Genus HAPLOCRINUS Steininger. 



Five species are described as belonging to the genus Haplocrinus, 

 but of these, specimens are missing for all but one. The latter, H. 

 hemisphericus Troost, is apparently identical with Pisocrinus milligani 

 Miller and Gurley. 



The name. Haplocrinus steininger is given to a specimen which 

 Troost considered to be closely related to but specifically distinct from 

 H. mespiliformis Goldfuss. As he does not say how his species differs 

 from that of Goldfuss and gives no figure or description of it, it is im- 

 possible to determine to what form the name applies and it therefore 

 becomes valueless. 



The publication of the description and figures of the remaining 

 three of Troost's species give them the same standing they would 

 have had if published earlier and the discovery of similar specimens 

 or comparison of the figures with specimens now in the hands of 

 collectors may lead to a more accurate determination of their affini- 

 ties than is now possible. 



HAPLOCRINUS OVALIS Troost. 



Plate 4, fig. 3. 



Haplocrinites ovalis Troost, Proc. Amer. Ass. Adv. Sci. (read 1849), 1850, p. 61 



(nomen nudum); MSS., 1850. 

 Haplocrinus ovalis Shumard, Trans. Acad. Sci. St. Louis, II, No. 2, 1866, p. 



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



III, 1886, p. 159 (catalogue name). — Miller, North Amer. Geol. and Pal., 



1889, p. 252 (catalogue name). 



The original description is as follows : 



It differs from Haplocrinus hemisphericus [Pisocrinus milligani Miller and Gurley] 

 in being more elongated, and transverse circular, whereas the H. hemisphericus is 

 pentagonal and compressed. 



Formation and locality. — Brownsport limestone. Decatur County, 

 Tennessee. 



HAPLOCRINUS GRANULATUS Troost. 



Plate 4, figs. 4, 5. 



Haplocrinites granulatus Troost, Proc. Amer. Ass. Adv. Sci., II (read 1849), 

 1850, p. 61 (nomen nudum); MSS., 1850. 



