40 University Geological Survey of Kansas. 



stead of being one-fourth or one-fifth the size of the radials, are 

 nearly as large. The costals show a marked spinous develop- 

 ment on the upper side, but in one of the figures (Geol. Surv. 

 111., V, pi. xxiv, fig. 6) of the Illinois forms the costal is shown 

 as being somewhat extended above. It is quite different from 

 the figure of the species by White above referred to, in being 

 quite plain and in having the plates less convex. It is also 

 more sharply pentagonal in outline than most of the members 

 of the species. However, this is a somewhat variable species, 

 and our specimen is probably a true E. typus, but presenting 

 interesting variant features. 



EUPACHYCRINUS. 



Meek and Worthen, Proc. Acad. Nat. Sci. Phil., p. 169, (1865). 



Eupachycrinus magister. Plate VI, figs. 3-3b. 



JEujyachycrinus magister Miller and Gurley, Jour. Cine. Soc. Nat. Hist., 

 xm, p. 4, pi. i, ff. 1, 2; 16th Rep. St. Geol. Ind., p. 328, pi. i, ff. 1, 2, 

 pi. x, ff. 6-8, (1890); Keyes, Geol. Surv. Mo., iv, p. 218, pi. xxvn, ff. 

 la, b, 3. 



Original description : " This species is very large ; calyx low 

 and broad, somewhat saucer-shaped, bulged a little on the 

 azygous side, height about half the width, sutures deep, ex- 

 cavation extending about half the thickness of the plates, plates 

 very strongly tuberculated, tubercles conical, elongated, and ir- 

 regular in form and distribution. The five basals [infrabasals] 

 are sunk in a cavity on the other side, projecting only half their 

 length beyond the column ; even this projection is tubercular ; 

 they form in the interior of the calyx a pyramid, which is 

 pierced at the summit by a five-rayed opening connecting with 

 the canal in the center of the column ; the points of the rays 

 are rounded. The basal plates are made pentagonal by the 

 truncation made at the points of the rays for the central canal. 

 The diagrammatic views which have been made of the basal 

 plates in this genus are incorrect, in so far as they indicate a 

 pentagonal opening with the angles directed toward the sutures, 

 instead of truncating the plates with the concave depression for 

 the five-rayed opening to the columnar canal. The two basals 

 on the azygous side of the species before us are larger than the 

 others, being nearly as large as the other three. 



