244 The Ohio Journal of Science [Vol. XVII, No. 7, 



In Habrocrinus farringtoni, Slocom, from the Racine near 

 Lemont, Illinois, the arrangement of the plates of the anal 

 interradial area agrees with that of Habrocrinus benedicti. 



In Habrocrinus lemontensis , Slocom, from the Racine near 

 Lemont, Illinois, the small size and quadrangular form of the 

 first costals is sufficient to distinguish this species from any 

 other described form of Habrocrinus. 



Periechocrinus tennesseensis, Hall and Whitfield. Plate X, Fig. 3. 



Saccocrinus tennesseensis, Hall and Whitfield, Geol. Surv. Ohio, Pal. 2, 1875, 

 p. 125, pi. 6, fig. 10. 



This Species was described and figured from a specimen 

 collected by Prof. Edward Orton in the Cedarville limestone at 

 Cedarville, Ohio, but it is evident that he regarded a specimen 

 in the Troost collection, from the Brownsport division of the 

 Niagaran in western Tennessee, as the type. (Wood, Bull. U. S. 

 Nat. Mus., 64, 1909, p. 76, pi. 6, fig. 10). 



In the Ohio specimen figured by Hall and Whitfield, the 

 sides of the calyx diverge at an angle of about 20 degrees, the 

 basal plates diverging apparently at an angle of 105 degrees. 

 At the summit, the calyx is quite abruptly truncated, the 

 tegmen being comparatively flat. 



In another specimen, here figured, from the same horizon 

 and locality at Cedarville, Ohio, the lower radials and inter- 

 radials are slightly broader; and the lateral diameter of the 

 calyx is slightly greater; otherwise it agrees closely with the 

 type. 



Periechocrinus cylindricus, sp. nov. Plate X, Figs. lA, B. 



Calyx, above the basals, sub-cylindrical, the sides diverging at 

 angles of about 10 degrees, or less. The convex basals diverge so as 

 to form an angle of about 90 degrees with the basal part of the calyx. 

 The top of the calyx is abruptly truncated, the tegmen being compar- 

 atively flat, as in Periechocrinus tennesseensis, to which the species may 

 be regarded as closely related. Four arms for each ray. 



Area of attachment for the column very small, not exceeding 2 

 millimeters in diameter. Three basals, convex. Radials and first 

 plate of the anal series considerably elongated, the length in extreme 

 cases equalling twice the width. The suture line between the radials 

 and the first one in each of the series of costals is very narrow, the 

 latter also being conspicuously elongated and tapering to a narrow 

 width at the base. As in other species of Periechocrinus, there are two 

 costals, two pairs of distichals, and four pairs of palmers in each ray. 

 The first interbrachial plate is large, the first and second pairs of inter- 



