Dec, 1920] Cystids and Blastoids - 75 



also the characteristic cuneate elevations at the top and bottom of the second 

 series of plates. C, Basal view of the same, showing both the cuneate and the 

 oblong elevations. At the center is a small triradiate structure, of which the 

 median ray points toward the right anterior interradius. The stem appears to 

 have been of remarkably small size. Specimen numbered 21815, from the Van 

 Home collection in Walker Museum at Chicago University. D, Cast of interior 

 of another specimen, with anal aperture at lower margin of figure, left of the 

 median line. Specimen numbered 18943, from the Gurley collection at Chicago 

 University. From the Racine dolomite at Racine, Wisconsin. 



Fig. 12. Wellerocystis kimmswickensis Gen. et Sp. nov. 



A, Viewed from above, with anus. B, Lateral view, with anus on upper right- 

 hand side, showing that the arm plates occur in single series; along the arm curving 

 around the anal aperture these arm-plates are seen to line only one side of the 

 main food-groove. The arm on the left side of the anal aperture is curved but 

 appears straight from the point of view seen in the figure. A third arm Hnes the 

 upper left-hand margin of the figure. Specimen numbered 10727, collected by 

 Prof. Stuart Weller, and preserved in Walker Museum of Chicago University. 

 From the Kimmswick limestone near Glen Park, Missouri. 



Fig. 13. Allocystites hanimelli Miller. 



A, Viewed from above, with aperture at the top of the figure apparently 

 pentagonal in form and elevated above the general surface of the theca. The 

 transverse ridge near the middle of the figure is interpreted as locating the 

 madreporite. The anal aperture is slightly below the middle of the figure and is 

 more or less quadrangular in outline. B. Specimen numbered 6006, in Walker 

 Museum of Chicago University. From the Osgood formation on Rikers Ridge, 

 northeast of Madison, Indiana. 



Fig. 14. Troostocrinus reinwardti minimus Var. nov. 



Lateral view, with left anterior radial in front. Specimen numbered 14791, 

 collected by Dr. H. E. W^ilson, and preserved in Walker Museum of Chicago 

 University. Found 6 miles west of Sb. Marys, Missouri. 



Fig. 15. Troostocrinus sp. 



Lateral view, with right posterior radial in front. Specimen numbered 22907, 

 from the Van Home collection,in Walker Museum at Chicago University. From 

 the Racine dolomite at the Bridgeport quarry, at Chicago, Illinois. 



PiCi. 16. Troostocrinus sanctipaulensis Sp. nov. 



Lateral view, with right posterior radial in front. Specimen numbered 22909, 

 from the Washburn collection, in Walker Museum at Chicago University. From 

 the top ol the Laurel limestone at St. Paul, Indiana. 



Fig. 17. Cyclocystoides (?) illinoisensis Miller and Gurley. 



A, Part of the main ring consisting of large plates, with a trace of the sur- 

 rounding peripheral margin, consisting of small imbricating plates. Type of the 

 species, numbered 6051 A in the collections of Walker Museum at Chicago Uni- 

 versity; the original of figure 27 on Plate 5 of Bull. 6, Illinois State Mus. Nat. 

 Hist., 1895. Found in the Orchard Creek shale, south of Thebes, Illinois. B, A 

 more complete specimen from the Savage collection at the University of Illinois, 

 found at the same locality and horizon. 



Fig. 18. Savagella ornatus Savage. 



Specimen badly weathered, some of the lower plates of the ring of large plates 

 considerably displaced, but their position indicated by depressions in the rock. 

 Part of the peripheral margin of small imbricating plates preserved. Original of 

 Fig. 28 on PI. 5, of Bull. 6, Illinois State Mus. Nat. Hist., 1895. From the Orchard 

 Creek shale, south of Thebes, Illinois. 



