PISOCRINIDAE 
75 
Ste. Genevieve County, Missouri. As the first American species of Pisocrinus to be de- 
scribed, there is a tendency to identify as P. gemmiformis any small, globose form, which 
may in some cases be the younger stage of other species. I have found this to be the case in 
the Tennessee collections. The one thing certain is that the species is characteristic of the 
typical Laurel formation. The oral plates are shown in figs. 8, Sa. 
Horizon and locality. Laurel formation and perhaps Osgood, Niagaran ; St. Paul, Osgood, 
Madison, Indiana, and possibly other localities as noted. I have figured a specimen from 
Gotland, plate 25, figure 13, which has all the characters of this species. 
Pisocrinus baccula Miller and Gurley 
Plate 2^, figs, p-13 
Pisocrinus baccula Miller and Gurley, Bull. 7, Illinois St. Mus., 1895, P- 79. pb 5. figs- 23-26. 
A relatively large species, maximum specimens 5 mm. high by 8 mm. wide. 
Calyx globose to ovoid, widest in lower third, contracting upwards. RR and RA 
curving sharply inward, forming a broad triangular base by which the calyx 
rests. BB almost wholly concealed in shallow concavity, only points of larger 
plates sometimes visible from side; outline of base seen from below obtusely 
triangular. Radial facets narrow, contracting upwards ; processes large, spear- 
head shape. Arms longer than in preceding species. 
The most characteristic species of the Laurel limestone at St. Paul, and not recognized 
elsewhere. It is associated with P. gemmiformis, but whether in the same layers cannot be 
ascertained — presumably not, as the formation is thick, and the material of the quarry dumps, 
from which most of the specimens are collected, is intermingled from different levels. It 
differs from that species in almost every essential character, especially in the radial facets 
and processes, and is recognizable at a glance in adult specimens from all other species by its 
broad, triangular base. It is abundant at the type locality, and is found in various sizes from 
3 to 8 mm. in diameter. 
Horizon and locality. Laurel formation, Niagaran ; St. Paul, Indiana. 
Pisocrinus granulosus Rowley 
Plate 23, figs. 3/-3P 
Pisocrinus granulosus Rowley, Am. Geol., 1904, p. 269, pi. 16, figs. 1-3. 
A medium sized species. Calyx globose, contracting at the arm-bases, about 
as high as wide, a maximum specimen being 5.5 by 6.5 mm., smaller ones about 
equal. Base convex, with very small column-facet, sharply indented; basals of 
good size, angles of largest ones visible from side view. Radial facets small, 
dove-tailed; processes large, broadly rounded, angular to spear-head shape. 
Surface smooth to granulose, or tubercular. 
Professor Rowley’s types were from brownish or reddish clays in the Bainbridge forma- 
tion of Ste. Genevieve County, Missouri, associated with his other species, P. spherictis, and 
some other forms, to which there is to be added P. tennesseensis as recently discovered by 
Dr. Weller. Among my Tennessee collections is a series of specimens from red clays of the 
Dixon formation at the top of Safford’s variegated bed, just below the Beech River. They 
partake of the color of the matrix, in which they differ from all the other Tennessee occur- 
