BATOCRINIDAE 
43 
DESMIDOCRINUS Angelin 
Plate 7 
Desmidocrinus Angelin, Icon. Crin. Suecc., 1878. p. 5.— Wachsmuth and Springer, Rev. Pal., 2, 1881, 
p. 108. — Bather, Treatise on Zool., 3, 1900, p. 166. — Zittel-Eastinan, 2d ed., 1913, p. 194. — Jaekel, 
Phylogenie und System, 1918, p. 37. 
Calyx as in Carpocrinus, but with iBr few, anals not in prominent row, 
arms irregular, 3, 4, or perhaps 5, to the ray, uniserial; brachials quadrangular. 
Genotype. Desmidocrinus pcntadacfylus Angelin. 
Distribution. Silurian ; Gotland, England, America. 
Desmidocrinus laurelianus new species 
Plate 7, figs. 24-241? 
This and the succeeding species are referred to the above Gotlandian genus 
because of the increase of arms above 10, and the smaller iBr areas. Here the 
latter consist chiefly of a single large plate. In both the anal interradius is fully 
developed, but not in the form of a raised vertical row as m.Carpocriniis. In 
this the ray branches on the second IIBr. Cup plates are convex and smooth. 
Horizon and locality. Laurel limestone, Niagaran ; St. Paul, Indiana. 
Desmidocrinus dubius new species 
Plate 7, fig. 25 
Distinguished from the preceding by the mode of arm-branching, which 
here occurs first on about the sixth IIBr, and perhaps again on one ramus, thus 
giving 4 or 5 arms to the ray. The calyx is more elongate and cup more tur- 
binate, and the reference to the genus is made wflth some doubt. 
Horizon and locality, same as last. 
Cylicocrinus canaliculatus S. A. Miller 
Plate 7, figs. 26-2(4 
Cylicocrinus canaliculatus Miller, i8th .Vnn. Rep. Indiana Dep. Geol., 1894, p. 285 (adv. sheets, 1892, p. 31), 
pi. 5, figs. 13, 14. — As Barrandeocriniis, Wachsmuth and Springer, N. A. Crin. Cam., 1897, pp. 484, 
485. — Bather, Treatise on Zool., 3, 1900, p. 166. — Zittel-Eastman, Textb. Pal., 2d ed., 1913, p. 195. — • 
Bassler, Bibliogr. Inde.x, 1915, p. lOi. 
The mystery surrounding the relations of the genus founded upon this species as type 
has not been solved by any of the recently acquired material, by which our information is 
still limited to the dorsal cup below the arm-bases ; it remains insufficiently known for a 
generic definition. It has the calyx of the Batocrininae, similar in all visible respects to that 
of the Swedish Barrandeocrinus with the recumbent arms — a similarity which led Wachsmuth 
and Springer to think it might possibly belong to that genus. The specimens I have since 
obtained show a thin, flange-like projection at the base which seem to me inconsistent with 
the close enveloping of the cup by the pendent arms such as is indicated by the various figures 
of Barrandeocrinus, for example in my recent paper on Lhiusual Forms of Fossil Crinoids, 
Proc. Lh S. Nat. Mus., 67, 1926, pi. 9, figs. 6-7. 
Horizon and locality. Laurel limestone. Niagaran ; St. Paul, Indiana. 
