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SMITHSONIAN INSTITUTION 
short, with not over two or three long brachials beyond the first short one, taper- 
ing to a pointed apex. 
This is the most common species of the Tennessee area, occurring by the hundreds at 
various localities in the Brownsport group. It is what Miller and Gurley undertook to de- 
scribe as P. mUliganae, but they entirely missed the prime character of the hidden basals, by 
which alone it is distinguished from P. gorbyi, and which it shares with P. sphericus of 
Rowley. Although the authors declare emphatically that their species has “ large basals, seen 
in side view even plainer than in P. gorbyi/’ this does not appear in their figures ; and the 
type specimens, formerly in the collection of Mrs. Milligan and now in my possession, show 
the large radials recurving deep into the basal pit. It is a singular fact that it should have 
remained for a foreign author, purely in an incidental way, to give the valid name to the 
most abundant of all the Pisocrinus species ; but Bather’s description is perfectly correct, and 
will hold. 
The characters are distinctive, as appears by several figures on plate 23 showing the 
form in all stages, especially the exact location and minute size of the basals as seen in the 
fractured cross-section at figure 29. The great size and deep undercutting of the spear-head 
processes is a striking feature of this species. In some specimens, such as figure 18, they are 
almost as high as the remaining portion of the cup, and in general they occupy over a third 
the total height of the cup measured to their angular points. 
The wealth of material in hand affords full information regarding the arms, of which 
I figure 4 specimens. All exhibit the same elongated brachials, with a tendency to a decided 
taper. Aside from its typical region in Tennessee, the species has been recognized sparsely in 
Missouri and Illinois. 
Horizon and locality. Brownsport group of the Niagaran. Collected in all glades in 
Decatur County, and in excavations at 4 different localities along Beech River, and at 6 other 
localities in Perry and Wayne counties, Tennessee. In collections from the glades there may be 
some intermingling with P. sphericus, but wherever quinquelobus was found in place it did 
not intergrade from lobate to round. Also in the Bainbridge limestone, Ste. Genevieve 
County, Missouri, and Racine dolomite of the Chicago area. In the sunken basals this species 
finds a parallel in P. ollula of Gotland, as shown by figures 8, 9, 10 of plate 25. 
Pisocrinus gorbyi S. A. Miller 
Plate 23, figs. 40-43 
Pisocrinus gorbyi Miller, 17th Ann. Rep. Indiana Dep. Geol., 1892, p. 640, pi. 6, figs. 17-20 (adv. sheets, 
1891, p. 30) ; N. A. Geol. Pal., ist App., 1892, p. 681, fig. 1243. — Rowley, Am. Geol., 1904, p. 269, 
pi. 16, figs. 4-7. 
A small species. Similar to P. quinquelobus except that the basals, instead 
of being hidden in a cavity, form a triangle, partly occupying a shallow depres- 
sion, and are more or less visible in a side view. Radial facets rather narrow ; 
processes large, lance-head shape. Surface usually smooth, perhaps sometimes 
tubercular. 
Miller described under this species specimens from two remote areas, northern Indiana 
and western Tennessee, which agreed in having a lobate calyx. The Tennessee specimens were 
afterwards separated by Miller and Gurley under the name P. mUliganae, which they pro- 
posed for the prolific species already named by Bather F. quinquelobus. The original descrip- 
tion holds good for the Indiana form, which is fairly common at its type locality. It is readily 
distinguished from the other two species of that area by its lobed calyx, and it is important 
