PLATTCRINID^. 659 



Platycrinus insolens Rowley and Hare. 



Plate LXXI. Fig. 15. 



1891. Kausas City Scientist, p. 98, Plate 2, Fig. 4. 



Type of P. lurUngtonensis ; described from the basals and radials. These 

 plates form a moderately small, spreading cup, with very slightly convex, 

 nearly straight sides, and broadly truncated base ; cross-section near the 

 upper end obscurely pentangular. Plates rather strong. 



Base saucer-shaped ; upper face produced into sharp angles ; lower face 

 perfectly flat, spreading outward into a short, well defined rim, fully twice 

 as wide as the column, and somewhat fluted at the margin; column facet 

 round. Interbasal sutures invisible ; basi-radial and interradial sutures 

 slightly depressed. Eadials about one fifth wider at the top than at the 

 bottom, their length equal to their greatest width ; longitudinally convex, a 

 little contracted at the upper end ; the faces supporting the interradial pieces 

 almost horizontal, and but slightly truncated at the anal side. Articular 

 facets occupying one third the width of the plates ; directed obliquely upward, 

 their surfaces being covered with fine radiating striae and an obscure trans- 

 verse ridge, but without perforation. 



Horizon and Locality. — Chouteau limestone ; near Curi'yville, Mo. 



Types in the collection of Mr. Rowley. 



Remarks. — This species resembles P. (sguitermcs Miller ; but the latter 

 has a more concave base, the facets of the radials are more projecting and 

 directed almost horizontally. It also approaches P. Brittsi, but the radial 

 facets are much wider and larger generally. 



Platycrinus Britsi S. A. Miller. 

 Plate LXXI. Fig. 10. 



1891. S. A, MiLLEE ; Bull. No. 4, Geol. Surr. Missouri, p. 23, Plate 3, Figs. 3 and 4. 



Comparable with P. cequilerniis Miller, and P. insolens Eowley and 

 Hare. Of medium size. Calyx to the top of the radials cup-shaped, 

 wider than high, broadly truncated at the bottom, the sides convex, 

 more rapidly expanding at the basals than at the radials. Plates thick. 



