PLATE XV. 



Orophocrinus verus, Cumb., sp., p. 290. 



Page 



Fig. 1. Radial view of a typical example. Carboniferous Limestone, Lancashire. x 2. 11 



Fig. 2. Summit view of another specimen, with the long hydrospire-clefts well shown. 



xl| 97 



Fig. 3. Anal interradius of a more inflated variety, showing the position of the anpl deltoid. 



Natural size ■ 291 



Fig. 4. A radial sinus, with the lancet-plate and the other ambulacral plates removed, so 

 as to expose the under lancet-plate, the ambulacral opening, the hydrospire-clefts, 

 and the tops of the hydrospires seen through them. x 4 47 



Orophocrinus pentangularis, Miller, sp., p. 292. 

 Fig. 5. Summit view of a specimen in which the deltoid plates are visible, and also one 

 ambulacrum with the under lancet-plate exposed. Carboniferous Limestone, 



Lancashire. x \\ 90 



Fig. 6. Interradial view of the same specimen, which is broken at the base. xl|. . . 11 



Fig. 7. Portion of an ambulacrum, with the grooved lancet-plate exposed in the 



middle line, and large deep pinnule-sockets between the side plates. x 12 . 61 



O. pentangularis, Miller, var. Waterhousianus, de Kon., var., p. 293. 

 Fig. 8. Summit view of a rather malformed individual, with the lancet-plates removed 



from two of the sinuses. Carboniferous Limestone, Belgium. x 1^ ... 90 



Fig. 9. Radial view of the same specimen, with an additional interpolated, narrow basal 



plate. Natural size 11 



Fig. 10. A radial sinus with the ambulacral structures removed so as to expose the under 



lancet-plate, which is partially broken away, thus laying open the visceral cavity. 



The tops of the hydrospire-folds are visible in the spiracular clefts. x 3. .47 



Orophocrinus stelliformis, 0. fy S., sp., p. 287. 



Fig. 11. The ventral aspect of a well-preserved specimen with a closed peristome, curved 

 and elongated spiracles, and suhpetaloid ambulacra. Subcarboniferous, Iowa. 

 Coll. Wachsmuth. x 99 



Fig. 12. Enlarged view of the central summit-plates and their extensions over the ambulacra. 



x8 68 



Fig. 13. A dissected ambulacrum of the specimen figured on PI. XI. with the lancet-plate 

 broken near its proximal end, a well-defined under lancet-plate, and very short 

 spiracles. x 4 47 



Fig. 14. Portion of an ambulacrum, showing the groove of the lancet-plate in the middle line, 

 and the oval sockets between the side plates, some of them filled in with calcite, 

 the others empty. The lines at the sides are the distal cuds of the spiracles. 

 ('oil. Wachsmuth. x 10 61 



Fig. 15. The interior of a calyx seen from below, with the hydrospires visible at the sides of 



the ambulacra. Coll. Wachsmuth, x~ 91 



