448 SMITHSONIAN INSTITUTION 



Kirk {op. cit., p. 113) disagrees with the provisional reference of the genus to the 

 Flexibilia, but does not undertake to determine its relations. 



P. H. Carpenter, in the Challenger Report on the Stalked Crinoids, page 211 et scq., 

 discussed the systematic position of Holopus, which he placed in the family Holopidae, 

 including Eudesicrinus, Cyathidium, and Cotylecrinas; and in that connection he stated 

 that Edriocrinus is "very closely allied to the recent Holopus and to Cotylecrinus" — differ- 

 ing from them only in the presence of the anal plate, which difference, as pointed out by 

 Meek and Worthen, is the same as between He.vacrinus and Platycrinus. These two genera, 

 however, he says " are both Paleocrinoids ; but Belemnocrinus and Rhizocrinus, a Paleo- 

 crinoid and a Neocrinoid respectively, are related in precisely the same way." 



Mr. Austin H. Clark does not think it possible that Edriocrinus can be closely related to 

 Holopus. In a recent paper 1 he expresses the opinion that " the pentacrinites, the comatulids 

 and Holopus are very closely related, in spite of their extraordinary superficial dissimilarity." 



The geological range of Edriocrinus is restricted to the Helderbergian and Oriskany 

 of the Lower Devonian, and it is not certainly known outside of America, although Jaekel 

 thinks Lodanella mira Kayser may belong to it. The new species indicated in the foregoing 

 remarks added to those heretofore described make a total of nine, two of which are repre- 

 sented by the complete crown, three by the calyx, and four by the fused base only. Diagnoses 

 of them all, in addition to that of the genus already given, in view of the new information now 

 obtained, may be stated as follows : 



Section I 

 Free in the adult stage, with fused basals rounded belozv. 



Edriocrinus pocilliformis Hall 



Edriocrinus pocilliformis Hall, Nat. Hist. N. Y. Pal. Ill, 1859, p. 121, PI. V, figs. 8-12.— Meek and Worthen, 

 Geol. Sur. Illinois III, 1868, p. 370, PL VII, figs. 50, &.— Wachsmuth and Springer, Rev. Pal. Ill, 

 Sec. 2, p. 266. — Keyes, Geol. Surv. Missouri, IV, 1894, p. 221, PI. XXX, fig. 7. — Talbot, Am. Jour. 

 Sci. (4) XX, 1905, p. 23, pi. 4, figs. 1-6. — Maryland Geol. Surv. Lower Devonian, 1913, p. 257, 

 PI. XL, figs. 13-15. 



Type of the genus. 



A small species, known only by the calyx. Base small, low hemispheric, 

 broadly convex, expanding upward; height to width about as 1 to 1.3; speci- 

 mens ranging in size from 4 to 15 mm. high and 7 to 20 mm. wide at basi- 

 radial suture. Radial circlet cylindrical, longer than wide, and slightly longer 

 than the base; anal plate narrower than radials. Traces of a narrow indented 

 scar are occasionally seen on the rounded base, and radiating ridges on the 

 ventral surface. 



Type. American Museum Natural History, New York. 



Horizon and locality. Helderbergian, New Scotland formation, Albany County, New 

 York; Perry County, Missouri. 



1 The systematic position of the crinoid genus Holopus, Jour. Washington Academy of Sciences, March, 

 1919, vol. 9, pp. 136-138. 



