39 



wardly, at an angle of about forty degrees below a horizontal 

 Line, Cor the second radials. The superior lateral sides come 

 together, at the sutures, so as to form a slight angle. 



The first azygous plate broadly truncates a subradial. It is 

 subquadrate in outline, but slightly expands upward. It is a 

 little wider than high. 



The general form, low basals, single azygous plate, thick 

 plates and surface ornamentation readily distinguish this spe- 

 cies from all others. 



Found by Dr. M. N. Elrod, in whose honor the specific name 

 is given, in the St. Louis Group, at Spergen Hill. Indiana, and 

 now in the collection of Wm. F. E. Gurley. 



POTERIOCRINUS PULASKIENSIS, n. Sp. 



Piute III, Fig. 26, azygous side; Fig. 27, opposite side, showing 

 two plates, in tiro of the arms, above the first radials. 



Species medium size. Calyx broadly truncated, and conoidal 

 above or like the frustum of a cone. Plates convex and su- 

 tures depressed, at the angles, and a pore penetrate- the calyx, 

 at every angle, in the same manner that they do in P. broad- 

 headi; though then do not seem to be any pores between the 

 angles as in that species. Diameter a little more than the 

 height. 



Basals short and truncated by the column. Subradials large 

 and about as long as wide, three hexagonal, two heptagonal. 

 First radials about one-fourth wider than long, truncated the 

 entire width above and separated from the second plates by a 

 gaping suture. Second radials short. Third radials in the two 

 rays opposite the azygous area short and axillary. Indicating 

 that there are ten arms in this species. 



The first azygous plate is nearly as large as a subradial, 

 rests between the superior sloping sides of two subradials. sep 

 arates two first radials and supports the second and third azy- 

 gous plates which makes the plate hexagonal, though only 

 slightly truncated by the third azygous plate. The second azy 

 gous plate is only a little more than half as large as the first. 

 The third plate is not preserved in our specimen. 



This is an extraordinary species that doc- not require a com- 

 parison with any other for the purpose of distinguishing it. 



found by Prof. A. G. Wetherby, in the Kaskaskia Group, 

 in Pulaski, county, Kentucky, and now in the collection of 

 Win. F. E. Gurley. 



