EXPLANATION OF PLATE 4. 



Page. 

 Figs. 1, 2. Talarocrinus symmetricus (Lyon and Casseday), side and basal views. 



This is from Troost's type of Dsemonocrinites cornutus 41 



3. Haplocrinus ovalis Troost, side view of Troost's type-specimen 25 



4. Haplocrinus granulatus Troost, side view of the type-specimen 25 



5. Transverse section of the same specimen. 



6. 7, 8. Haplocrinus maximus Troost, side, basal, and top views of the 



type specimen 2G 



9. Coccocrinus bacca Roemer, side view of the specimen figured by 



Troost as Platycrinites Ann. Dixoni 29 



10. Ectenocrinus canadensis (Billings), a specimen partially embedded in 



the matrix. The plates of the calyx are incorrectly represented. . . 22 



11. Symbathocrinus robustus Shumard, side view. This is from Troost's 



type of Donacicrinites simplex 28 



12. 13, 14. Orbitremites granulatus (Roemer), side, top, and basal views of 



the specimen described by Troost as Granatocrinites globosus 21 



15, 16, 17. Side, top, and basal views of Troost's Granatocrinites cidari- 



formis 21 



18. Platycrinus insculptus Troost, view of basal plates 40 



124 



