Descriptions of Neio Crinoids. 249 



second scries, and four of them pointed below, witli tliis extremit}' em- 

 braced by the sub-radials between which they lie. The other plate of 

 this series, Avhich is immediatel}' at the right of the azj'gos area, is 

 truncated below, and rests upon the upper left lateral face of the ad- 

 jacent basal. All tlie plates of this range are slightly convex exteri- 

 orly and without ornamentation. 



Brachials — Five, irregularly quadrangular, higher than wide, and 

 alike in shape and size. As these plates are slightly narrowed at the 

 upper extremity, and somewhat excavated laterally and centrally, the 

 effect is to constrict this part of the specimens, making the diameter 

 at these plates much less than that at the first radial series. 



Azijgos plates — Five, the lower one pentagonal, and resting as 

 stated above, on the truncated inner middle angle of the first sub-ra- 

 dial contiguous to it. The others are hexagonal, and upon dissection 

 of the crinoid are shown to be the outer proximal portion of the 

 ventral tube, which, in this species, is made up of hexagonal plates, is 

 round, and tapers gradually upward. 



Arms — ^Five, composed of about fifty nearl}^ equal plates, wider than 

 high, and arranged in single series, as in t3'pical Graphiocrinus. The 

 articulating surfaces of the arm plates, as seen from the outside, are 

 nearh' parallel. The plates shorten towards the distal extremity of 

 the arns, causing the latter to taper gradually. An inner or lateral 

 view of the arms shows that here the plates are alternately thicker and 

 thinner upon each side, as every other has one extremity thickened 

 and dilated into a process with socket of attachment for the \ery stout 

 basal joint of the pinnulse. 



Pi iinulce— These are stout, short, few jointed, and taper gradualh' 

 from the arms outward. They are continued down from the tips of 

 the arms to the last plate, resting upon the brachials, which 

 brings them in immediate connection with the proximal end of the 

 ventral tube. 



Remarks — This is one of the rarest crinoids of the Kaskaskia 

 (Chester) Group of the Subcarboniferous, Pulaski county, Kentucky. 

 In the character of single series of arm plates it agrees with Oraphio- 

 crinus, from which it diff'ers in having but five arms, and a well-defined 

 under basal series. It has also aflSnities with Eupachycrinus, but differs 

 in the character of single arm plates. Its nearest alliance seems to be 

 with Cromi/ocriiius, Trautschold. There ai-e evidences, in one or two 

 specimens, that the arm furrows were covered in by a series of plates, 

 so arranged as to interlock in a zizag manner between the two rows of 

 pinnuloe. While this fact seems to be well shown, it is but the second 



