442 
Aug. F. Foerste 
the presence of numerous tubercles supposed to belong to the orig= 
inal ornamentation of the plates. In the original description it 
is stated that ^'the surface of all the plates is densely and beauti- 
fully tuberculated. This species is distinguished from all others, 
in rocks of the same age, by the tuberculated plates. ’ ' Asa matter 
of fact, all plates are not densely and beautifully tuberculated, and 
it is doubtful whether the tuberculation belongs to the plates, as an 
organic part of the same. 
If I have correctly interpreted the orientation of this specimen, 
then the transverse slit along the oral parts is parallel to a line 
drawn diagonally across the brachial valve of the Hebertella alveo- 
lata, upon which the specimen rests; this line is to be drawn from 
the right hand end of the hinge line to the left antero-lateral angle 
of the valve. The anterior parts of the theca lie nearer the anterior 
margin of the valve. The broad, peristomial plate, posterior to 
this slit, and the right one of the two plates immediately anterior 
to this slit appear to be preserved. There appear to be traces of 
the two posterior rays enclosing the supposed anal interambulac- 
ral area, but most of the plates within this area are missing and 
those present are more or less displaced and tilted at various 
angles, making their definite interpretation impossible. 
The right anterior, and anterior rays are strongly curved in a 
sinistral direction, but only the terminal parts are even fairly 
preserved. At the proximal end of the anterior ray, apparently 
one or two floor plates are exposed. Several floor plates belonging 
to the left anterior ray also appear present. They form a single 
series, are depressed along the center, are about as long as wide, 
and overlap each other in a proximal direction. Possibly the 
floor plates described by Aleek (Ohio Palentology, voL I, p. 55) 
belong to this Richmond species. Nearly all of the plates belong- 
ing to the left posterior interambulacral area of Agelacrinus 
faberi are missing. 
The plates of the interambulacral areas are of medium size, but 
the first circle of plates immediately exterior to the terminations 
of the ambulacral arms, belonging to the inner band of the pe- 
ripheral ring, consists of large transverse plates, varying between 
3 and 4 mm. in width. Exterior to these are about two circles 
of plates, nearer 2 mm. in width, between which and the margin 
there are two, three, or four successively smaller plates. In the 
original description it is stated that this species is ^^distinguished 
