INSERTAE SEDIS 449 



Edriocrinus occidentalis n. sp. 



PI. LXXVI, figs. 6-12 



A rather small species, known by the base only. Base small, elongate, 

 broadly rounded at lower end, with thick wall enclosing an inversely conical 

 tubular cavity which narrows downward, leaving the wall thickest at the lower 

 part; often constricted below the radial facet and expanding again towards 

 them. Height to width in average of 20 specimens showing all variations, 

 about as 1 to .75 ; specimens varying in size from 8 to 20 mm. high, and from 

 6 to 14 mm. wide at top. 



Types. In the author's collection. 



Horizon and locality. Helderbergian, Linden formation ; in cherts and clay bands, in 

 Stewart and Decatur counties, Tennessee, and in the equivalent New Scotland formation in 

 Allegheny County, Virginia. This is the species of Edriocrinus mentioned by Dr. Foerste 

 in Journal of Geology VII, 1903, pp. 682-7, as occurring " near the western end of the 

 exposures along the Cumberland River, west of Cumberland City," which he was inclined 

 to refer to the Camden chert. Dr. Bassler, who has since carefully reviewed the stratig- 

 raphy of that region, informs me that the Cumberland River exposures in question may 

 be properly included in the Linden. The correlation as above given of the beds on the east 

 flank of the Appalachian Mountains near Covington, Virginia, is upon the authority of 

 Dr. Ulrich, who assures me that the occurrence of the same species in the two areas might 

 well be expected. 



Edriocrinus explicatus n. sp. 



Plate LXXVI, figs. 13-15 



A smaller form than the last one, known from the base only. Base sub- 

 globose, widening slightly upward, with basals but slightly modified by secon- 

 dary growth and the sutures therefore observable. Height and width about 

 equal, and specimens varying from 5 to 9 mm. each way. 



Types. In the author's collection. 



Horizon and locality. Helderbergian, Linden formation, Perry County, Tennessee. 



Edriocrinus dispansus Kirk 



Plate LXXVI, figs. 1-5 



Edriocrinus dispansus Kirk, Proc. U. S. Nat. Mus., vol. 41, 191 1, p. 112, pi. n, figs. 1, 2. 



A medium-sized species, known only by the calyx. Base low, discoid, 

 usually with remnant of indented scar of attachment at younger stage. Calyx 

 with radials in position in form of an obscurely hexagonal, truncated pyramid, 

 contracted at the top of the radials to less than half its diameter at the base. 

 RR narrowing upward to short distal faces. Anal plate long, narrow, pro- 

 jecting in an angular apex above the line of radials. Height of base about 

 one-tenth its width; height to width of calyx about i to 1.8, varying in eight 

 specimens from 6 to 15 mm. high and 12 to 30 mm. wide at the base; width 



