73 TRANS. OF THE ACAD. OF SCTENCE. 
to an inch and a half long. Ihave in my collection a proboscis, 
. apparently belonging to this species, which bifurcates near its 
middle, and presents somewhat the form of the letter Y, the prongs 
being about half an inch long. 
The arms come off, at nearly right angles to the axis of the 
body, in groups of four, and sometimes five, separated by distinct 
intervals. The commencement of 21 arms is to be seen on one 
of the specimens figured, and 22 on the other. 4 
The column is unknown. 
Dimensions.—Height of body, including proboscis, 22 inches; 
do. of calyx, 4 inch; do. of base, 1 line; diameter of base, 6 lines; 
height of Ist radials, 2 lines; width, 34 lines. 
This fine species was figured, in 1847, by Prof. L. P. Yandell 
and the author of this paper, in a small pamphlet, entitled «Con- 
en. “ 
formation and lécalities.—It occurs at Button Mould Knob, 7 
miles south of Louisville, Kentucky, near the base of the Carbo- 
niferous System, in blue and yellow marly clay, associated with 
Productus punctatus, Chonetes Shumardiana, Orthis Michelini, 
ISSYt cynodon. ‘T have, ae 
found silicified specimens of this species, occupying the same_ 
geological position, at White's Creek Springs, a few miles from 
Nashville, Tennessee, : a 
The species is named in compliment to my friend, Prof. L. 
Yandell, of Louisville, Kentucky, whose valuable cabinet is F 
in beautiful examples of it, ae 
Homocaines ronypacryxvs, ( Shum.) 
PILI. Fig. 6, a, b. A 
Syn., Orarmocnistres. Christy’s “ Letters on Geology,” Pl. I, No. 7, & Pl.3, No. te 
he summit of this species is conical, the plates moderately 
- The base isa little cup, composed of lice esialt ntagonal pie+ 
. ces, a little higher than wide. narrow, dnieaei aa suf 
rounds the exterior border of each plate, within which the surfacé 
1s tumid, so that the base, when viewed from below, pane 
_ distinct pentalobate outline. The articular facet for the columl’ 
 {Pentagonal, and its diameter equal to about three-fourths the 
- Reight of the base, ae “eg 
