156 Cincinnati Society of Natural History. 



portion. The sutures of these plates, with the brachials, gape slightly 

 outward. 



Brachials — Five, pentagonal, higher than wide, equal in size and 

 shape. Very slightly constricted laterally in the central portion, the 

 lower faces being equal to those of the radials upon which they rest, 

 the upper bearing upon its sloping sides two arms. 



Azygous Plates — Arranged in two alternating rows, the lower plate 

 being upon the right ; it is pentagonal, and abuts upon the upper, 

 right hand sloping side of the basal below, the truncated inner angle 

 of the next one to the right, and the radial immediately over this. 

 The first plate above this, on the left side of the azygous area, is ir- 

 regularly pentagonal, resting upon the truncated upper face of the 

 basal below, and abutting upon the plate above described, the next 

 one above it in the series upon the right, and against the radial on the 

 left. Above these two the number and arrangement is not well shown. 



Arms — Ten, composed. of a single series of plates which are cunei- 

 form below, but lose this character above, becoming of equal thick- 

 ness from side to side of the arms. The sutures between these plates 

 are thus oblique to the axis of the rays below, but cross it at right 

 angles above. These plates are slightly wider in the center of the 

 arms, so that the latter taper ver}^ gradually above and below this 

 region. There are about fifty of these plates in each arm, which 

 undergo no divisions, all being simple throughout. 



PinnulcB — The few joints of these remaining are short and stout 

 but not in a condition to indicate anything further. 



Column — Small, round, composed of equal thin pieces, radiately 

 striated upon their articulating surfaces, and perforated by a circular 

 canal. 



Locality and Position — Pulaski county, Kentucky, in sub-carbon- 

 iferous rocks of the age of the Kaskaskia (Chester) Group. 



Beniarks — This species has the arm structure of typical Graphio- 

 crinus, from which, however, it differs totally in the arrangement of 

 the bod}' plates, which is that ot Poteriocrinus, or of that well-marked 

 division of this genus established by Wachsmuth and Springer, 

 under the name /iS'c^/^aZocrm i«5, from which it differs only in the fact 

 that the underbasals are not " bent upward." As these authors have, 

 however, referred the Poteriocrinus ivetherhyi, S. A. Miller, in which 

 the arrangement of the underbasals is identical, to Scytalocrinus, I 

 do not hesitate to place this species in the same division, which 

 might be very properly raised to generic rank. 



The specific name is given in honor of Charles Wachsmuth, of Bur- 



