6o 
SMITHSONIAN INSTITUTION 
Marsipocrinus excavatus new species 
Plate i6, figs, y-yh 
Calyx plano-convex, with basal pentagon abruptly sunken around a small, 
round column-facet. iBr projecting in small points. Tegmen conical, higher 
than cup; plates low, covered with small tubercles. Surface markings on cup 
coarse, with irregular strong wrinkles and obscure striae. Founded upon a 
single specimen 13 mm. high by 28 mm. wide, with basal pentagon about one 
third the total diameter. 
Porison and locality. Eucalyptocrinus zone of Beech River formation, Brownsport 
group, Niagaran ; Tuck’s Mill, Decatur County, Tennessee. 
Marsipocrinus concavus new species 
Plate 16, fig. 8 
Calyx with deep funnel-shaped basal cavity, involving part of the radials. 
Basal pentagon very small, almost covered by column at bottom of cavity, bor- 
dered by a thin rim. Radials long, extending far down into the basal cavity. 
Surface ornament strong, composed of some irregular striae, and concentric 
ridges roughly parallel to margins of pentagon. Tegmen and other parts 
unknown. 
A thoroughly distinct species, differing from all others as Pisocrinns qiiinqiielobus differs 
from species with large basals. Unfortunately represented by only a single imperfect speci- 
men consisting of basals and radials. 
Horizon and locality. Eucalyptocrinus zone of Beech River formation, Brownsport 
group, Niagaran; Tuck’s Mill, Decatur County, Tennessee. 
Marsipocrinus stellatus (Troost) 
Plate ly, figs, i-io 
Cupellaecrinites stellatus Troost, Am. Jour. Sci., 1849, p. 419; Proc. Am. Assn. Adv. Sci., 1850, p. 61 (nom. 
nud.). — Cupellaecrinns stellatus Shumard, Trans. Acad. ,Sci. St. Louis, 1866, p. 361. — Marsipocrinus 
stellatus (Troost) Wood, Bull. 64, U. S. Nat. Mus., 1909, p. 36, pi. 10, figs, i, 2. 
A rather small species, with dorsal cup perfectly smooth, ranging from 8 
and 10 mm. height of calyx to i6 and 24 mm. width. Calyx bi-convex, broadly 
spreading, with base flat or slightly convex. Basal pentagon about two fifths 
the total diameter; interbasal sutures often obscure. iBr with rather sharp pro- 
jecting lip. Arms directed horizontal, long and slender toward the extremities, 
two to the ray. Tegmen broadly rounded, smooth in interambulacral regions, 
or with scattering sharp nodes; ambulacra conspicuous from middle to arm- 
bases, with some outer branches leading to pinnule openings. Surface of cup 
entirely devoid of ornament. Stem stout, tapering distally dividing into terminal 
branches for attachment. 
The smooth surface in this species is not a matter of erosion, but is a thoroughly definite 
character, as is shown by at least a dozen specimens in the collection, mostly well preserved 
