Bemarks on the Trenton Limestone of Kentucky. 155 



Locality and Position — Mercer count}^, Kentucky, in the Middle 

 Trenton as tliere exposed. Two specimens, one of wliich is remarka- 

 bly perfect to the tips of the arms. 



Bemarks — It is with many doubts that I refer this beautiful crinoid 

 to this genus. In considering these doubts I have carefully compared 

 this with all the other species of Heterocrinus. 



I have also compared notes on this subject with Mr. Wachsmuth, to 

 whom I sent the specimens for e:S:amination, who sa3^s, "when I wrote 

 up the CyathocrlnidcE^ I was in doubt whether I should not place H, 

 juvenis under a new sub-genus. The size of the column compared with 

 the body is most remarkable, and I think the arrangement of the 

 plates differs from that of Heterocrinus simplex, at least." 



In this doubt Mr. Wachsmuth was fuUj^ justified, and it is a matter 

 to be regretted that he had not defined this little group, giving it 

 sub-generic rank at least. 



I hope to obtain other specimens from which the arrangement of the 

 azygous plates and adjacent ra3^s may be full}' determined; but with 

 the evidence at hand it is not at all difficult to separate this species 

 from any hitherto described. The specific name is given in honor of 

 that earnest and indefatigable palaeontologist, S. A. Miller, Esq., who 

 has contributed so many valuable writings, not only to Palaeontology, 

 but also to the subject of Geology at large. 



SCYTALOCRINUS WAOHSMUTHI, UOV. Sp, 

 (.Plate v., fig. 4, view of the symmetrical side.) 



Underhasals — FiA^e, pentagonal, about as wide as high, equal in size 

 and alike in form^ the lower, inner surfaces being slightly excavated 

 for the reception of the convex, upper surface of the first columnar 

 disc. 



Basals — Five, three hexagonal, slightly higher than wide, and 

 identical as to size and form. The two on the azj^gous side are hepta- 

 gonal, being rendered so by the truncation of the upper inner angle of 

 the one on the right ot this area, and of the upper angle of that on 

 the left, 



Badials — Five, four pentagonal, nearly equal in shape and size, 

 wider than high, regularly alternating with the basals. The one on 

 the right of the azygous area, slightly smaller than the other four, ir- 

 regularly quadrangular, and somewhat elevated above them. It rests 

 upon the truncated upper surface of the basal below. The upper ar- 

 ticulating face of these plates extends entirely across, and is striated 

 or slightly crenulated with fine ridges, radiating from the inner central 



