DIMEROCRINIDAE 
15 
Cyphocrinus gorbyi S. A. Miller 
Plate I, figs. 15-18 
Cyphocrinus gorbyi Miller, i8th Ann. Rep. Indiana Dep. Geol., 1894 (adv. sheets, 1892, p. 51), p. 305, pi. 7, 
figs. 14-16 . — Hyptiocrinus typus Wachsmuth and Springer, Am. Geol., 10, 1892, p. 138; N. A. Grin. 
Cam., 1897, p. 201, pi. 19, figs. 6 a-c. 
This genus, while contrasting in the hemispheric and drooping contour 
widely with the preceding, clearly exhibits the essential characters of the family 
in the construction of the calyx. The arms have not been found beyond slight 
remnants, from whiyh it is evident that they were biserial, stout and unbranched ; 
and from the appearance of the extremely elongate spinous ambulacrals upon 
the teginen surmounting the rays, and the direction of the arm-openings, it 
might be inferred that they were of the recumbent type, with the pinnules directed 
outward. 
Four specimens of the type species, which is cjuite abundant at the type locality, are 
fi.Sfured in order to show some details more fully than appeared in the original description. 
This applies especially to the interbrachial openings at the margin of the tegmen for fixed 
pinnules to the number of 4 or 6 between the rays and their divisions. These openings, 
formerly interpreted as “ respiratory pores,” are now traced in several Camerate genera with 
unbranched arms to a connection with the arm-grooA^e.^ 
Weller has described a species, C. chicagoensis, from the Racine dolomite of the Chicago 
area, but otherwise the form has only been found in the Laurel limestone at St. Paul, Indiana. 
This and the next following form were independently described by Wachsmuth and 
Springer and S. A. Miller in 1892. The Wachsmuth and Springer names were published in 
the American Geologist for September, 1S92, but owing to some delay in printing, that 
number of the magazine was not actually issued until some weeks after its purported date. 
Meantime Mr. Miller issued advance sheets of the i8th Rep. Geol. Indiana containing his 
new names, which were specially distributed to his correspondents. The claim was made that 
this distribution antedated the delivery of the magazine to its subscribers. Dr. Weller in con- 
nection with his Chicago species considered the question in the light of such evidence as could 
be obtained, and decided in favor of the priority of Miller’s names, which I have accepted. 
Horicson and locality. Laurel limestone, St Paul, Indiana. 
GAZACRINUS S. A. Miller 
Plate 2 
Gasacrinus Miller, i8th Rep. Geol. Dep. Indiana, 1894, p. 303 (adv. sheets, 1892, p. 49), N. A. Geol. Pal., 
1st App., 1892, p. 679; ibid., 2d App., 1894, p. 746. — Weller, Bull. Chicago Acad. Sci., 4, pt. i, 1900, 
p. 78, fig. 38 (synonymy discussed). — Bather, Treatise on Zooh, 3, 1900, p. 188, fig. 119. — Zittel- 
Eastman, Textb. Pal., 2d Ed. 1913, p. 187. — Jaekel, Phylogcnie und System, 1918, pp. 41, 80. — Bassler, 
Bibliogr. Index, 1915, p. 545. 
Idiocrinus Wachsmuth and Springer, Am. Geol., 10, 1892, p. 135; N. A. Grin. Cam., 1897, p. 202. 
Base concave, IBB confined to the cavity; iBr in cup limited to a single 
large plate in each interradius connecting with tegmen, that of posterior side 
following the truncate B ; arms biserial, simple, directed upwards. Anus without 
a tube. Tegmen composed of a few plates, crowned with a central pyramid. 
^ See Springer, Scyphocrinus, Smithsonian Inst., 1917, pp. 33-37. 
