BATOCRINIDAE 
45 
Periechocrinus tennesseensis (Hall) 
Plate 10, figs. 1-4 
Saccocrinus tennesseensis Hall, Geol. Surv. Ohio, Pal., 2, 1875, p. 125, pi. 6, fig. 10. — Periechocrinus tennes 
seensis, Wachsmuth and Springer, N. A. Crin. Cam., 1897, p. 528, pi. 50, fig. 4 (figured as Roemer’s 
type of Saccocrinus speciosus). — -Wood, Bull. 64, U. S. Nat. Mus., 1909, pp. 76, 78, pi. 6, fig. 10. — 
Saccocrinus speciosus Roemer (not Hall), Sil. Fauna Westl. Tennessee, i860, p. 42, pi. 3, figs. 3a-c. — 
Bassler, Bibliogr. Index, 1915, p. 956. 
The species is well known to collectors in the Tennessee area from the 
earliest times. Both Troost and Roemer recognized it, and in the modern col- 
lections it is not uncommon. It is rather on the border line between the two 
allied genera as they are here defined. I am figuring four specimens in order 
to show some of the minor variations which must be considered in any critical 
comparison of the described species. Some show the axial folds by obscure 
traces, and some scarcely at all ; but all have the slender calyx and narrow tur- 
binate base usually seen in the genus. The arms vary in different individuals 
not otherwise distinguishable, from 4 to 5 to the ray. The species has been 
found at the principal localities of the Brownsport group. 
Horizon and locality. Beech River and perhaps other formations of the Brownsport, 
Niagaran ; Decatur, Perry and Wayne counties, Tennessee. 
Periechocrinus sp. 
Plate 10, figs. 5, ga 
The crushed and damaged specimen here figured is of a distinctly different 
type from the preceding, and has much the character of the typical English 
form; it is the only one thus far found that seems to approach the European 
type so closely; if in better condition for observation it would doubtless bear 
close comparison with some of those species. The calyx walls are very thin, and 
the axial folds leading to the arms sharp and prominent. In the number of the 
branching, biserial arms, which seem to run to 7 or 8 to the ray, the specimen 
shows a significant resemblance to Angelin’s figures of P. moniliformis, Icon. 
Crin., pi. 19, figs. 14, 14b. 
Horizon and locality. Beech River formation, Niagaran ; Decatur County, Tennessee. 
SACCOCRINUS Hall 
Plate 10 
Saccocrinus Hall, Pal. New York, 2, 1852, p. 205; 28th Rep. New York St. Mi:s., 1879, p. 127.— Roemer, 
Sil. Fauna Westl. Tennessee, i860, p. 44. — Meek and Worthen, Geol. Surv. Illinois, 3, 1868, p. 347; 
ibid., 5, 1873, p. 394.— Zittel-Eastman, Textb. Pal., 2d ed., 1913, p. 194.— Bassler, Bibliogr. Index, 
1915, P. 954- 
Calyx arranged like Periechocrinus, but the arms from about 20 (excep- 
tionally 10) openings branch after becoming free, and are biserial both below 
and above the bifurcations. Plates usually thicker and more convex, and with- 
out axial folds. 
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