22 BULLETIN 64, UNITED STATES NATIONAL MUSEUM. 



statement that the granules of the latter run parallel to the sides of 

 the plates Hambach says: "This is an incorrect statement, because 

 the specimen shows just the reverse." 

 Cat. Nos. 33077, 33080, U.S.N.M. 



Class CRINOIDEA Miller. 



Subclass MONOCYCLICA Bather. 



Order MONOCYCLICA INADUNATA Bather 

 (Waehsmuth and Springer, in part, emend.) 



Family HETEROCRINID^ Zittel (emend. Waehsmuth and Springer) . 

 Genus ECTENOCRINUS S. A. Miller. 



ECTENOCRINUS CANADENSIS (Billings). 



Plate 4, fig. 10. 



Heterocrinites simplex Troost, Amer. Ass. Adv. Sci., II (read 1849), 1850, p. 60 



(catalogue name) ; MSS., 1850. 

 Heterocrinus canadensis Billings, Can. Org. Remains, Dec. IV, 1859, p. 48, pi. 



xiv, figs. ba-d. — Shumard, Trans. Acad. Sci. St. Louis, II, 1866, p. 377 



(catalogue name). — Wachsmuth and Springer, Rev. Palseocrinoidea, Pt. 3, 



1886, p. 206 (catalogue name). 

 Heterocrinus simplex Wachsmuth and Springer, Rev. Palseocrinoidea, Pt. 1, 



1879, p. 150 (catalogue name). 

 Ectenocrinus canadensis Miller, North Amer. Geol. and Pal., 1889, p. 242. 



The following remarks are by Troost: 



I found only a few mutilated specimens of this fossil in the Silurian strata in the 

 State of Tennessee, but I collected some perfect ones in the State of Kentucky which 

 were imbedded in a soft argillaceous limestone and I succeeded in developing some 

 perfect heads which were affixed to about two inches of their column, and some others 

 which were eroded in such a manner as to display their internal structure, from which 

 it appears that in the Heterocrinites [Ectenocrinus'] of Tennessee and Kentucky the 

 coronal integument terminates in an articulated fluted proboscis, which ascends 

 between the fingers [arms] to nearly where they terminate; and that the fingers [arms] 

 are furnished with tentacula or feathers [pinnulae]. These facts are not mentioned 

 by Hall [1847, p. 280]. Hall also mentions that the column is pentagonal, this also 

 does not agree with the Tennessee fossil. On a slab of limestone similar to that above 

 mentioned, which contains a great number of columns some of which are affixed to 

 mutilated heads, not a single • pentagonal column is found, they are all formed of 

 small and large alternating circular joints with rounded margin, as is represented on 

 the figure. 



Observations. — Meek united provisionally the Heterocrinus canadensis 

 Billings with his Heterocrinus simplex var. grandis, but wrote that 

 his species differs from H. canadensis in its shorter and more wedge- 

 shaped arm plates. For this reason it seems best to regard them as 

 distinct species unless a comparison of the types should show them 

 to be more nearly alike than the description indicates. 



