CRINOID GENUS SCYPHOCRINUS 55 



While distinctly of the type of S. pyburnensis, the zone of greatest width 

 is much lower, and the basal expansion of the calyx at a considerably wider 

 angle. The low, flat plates and absence of distinct sculpturing also distinguish 

 it, although this character must not be too much depended upon as the appear- 

 ance may be due to erosion. 



Holotype. — In U. S. National Museum. 



Horizon and locality. — Helderbergian ; Haragan limestone, near Dough- 

 erty, Oklahoma. 



8. SCYPHOCRINUS GIBBOSUS n. Sp. 

 Plate IX, figs. 30, b 



Calyx small, broadly spheroidal below, widest about the middle, contract- 

 ing toward the arm-bases. Base very small. Interbrachials not protuberant. 

 Plates highly tumid, with strong connecting ridges and pits. 



Dimensions of type specimen : Height of calyx to IIBr 3 , 25 mm. ; width 

 at IIBr, 30 mm. 



A single imperfect calyx found in the Camarocrinus horizon of Oklahoma 

 suggested the proposal of this species; it is preserved only to the height of the 

 third secundibrachs, and the basal plates are wanting. Among the Hardin 

 County, Tennessee, material from the Pyburn's Bluff locality, there are three 

 small specimens of about the same size as this agreeing in the characters noted, 

 one of them a perfect calyx, which I have figured for comparison, Plate VIII, 

 figure 7. They have the facies of 5*. pyburnensis, without the projecting inter- 

 brachials, the absence of which, however, may be a juvenile character. The 

 two forms are evidently of a closely similar type, but whether identical can 

 only be determined by discovery of better material from the Oklahoma locality. 



Holotype. — In the U. S. National Museum. 



Horizon and locality. — Helderbergian ; Haragan limestone, Franks, Okla- 

 homa, and (?) Hardin County, Tennessee. 



