MELOCRINID^. 285 



3 X 10^ each series supporting two arms, or twenty from the calyx. The 

 two inner arms branch three timeS;, the outer ones remain simple. Above 

 the last bifurcation, according to Hall, the arms are composed of a " double 

 series of wedge-formed plates, and below these points of a simple series of 

 quadrangular plates," with rounded pinnules. 

 Horizon and Locality. — Same as last. 



Mariacrinus aureatus S. A. Miller. 



(After Miller.) 

 1891. Adv. Sheets 17th Eep. Geol. Surv. of Indiana, p. 34, Plate 6, Pig. 36. 



Calyx very small. Dorsal cup bowl-shaped ; plates covered with angular 

 ridges passing out from their centres. Basals four, unequal; exposed 

 beyond the column. Radials the largest plates of the calyx, wider than 

 high. First costals a little smaller, their width greater than the length -, 

 pentangular or hexangular. Second costals as long as wide. Distichals two 

 in the three anterior rays, three in the posterior ones ; the second plate of 

 the former axillary. Interradial areas elongate, subovate. Eegular sides 

 composed of seven or eight plates : 1, 2, 2, 2 ; the first nearly as large 

 as the radials. Interdistichals one or two. The anal side has nine or ten 

 plates, there being three in the second, and four in the third row ; the plates 

 of the upper row very small. Arm structure and tegmen not preserved in 

 the specimens. 



Horizon and LocaUty. — Niagara group ; St. Paul, Ind. 



MACROSTYLOCRINUS Hall. 



1852. Hall; Palseont. N. York, A^ol. IL, p. 203. 



1857. Pictet; Traite de Paleontologie, Yol. IV., p. 329. 



1862. DuJARDiN and Hupe ; Hist, natur. des Zooph. Echm., p. 149. 



1863. Hall ; Trans. Alb. Inst., Yol. lY., p. 207 (Abstr. p. 12). 



1879. Hall ; Mus. edit. 28th Rep. N. Y. State Mus. Nat. Hist., p. 128. 



1879. ZiTTEL ; Handb. d. Pateont, Yol. I., p. 368. 



1881. W. and Sp. ; Revision Palseocr., Part II., p. 102 ; also Proceed. Acad. Nat. Sci. Phila., p. 276. 



1881. Hall; 11th Ann. Rep. Geol. of Ohio, p. 256. 



1882. Ringtjeberg; Journ. Cincin. Soc. Nat. Hist., Yol. Y., p. 119. 



1882. De Loriol; Paleont. Prancaise, Tome XL, Crinoides, p. 56. 



1883. W. and Sp. ; Revision PalEeocr., Part III., p. 102; also Proceed. Acad. Nat. Sci. Phila.,p. 324. 

 Syn. Aetinocrvws (in part) — Lyon; Proceed. Acad. Nat. Sci. Phila., 1861, p. 411. 



Syn. CyafMcrinus (in part) — Hall; Doc. edit., 28th Vol., N. Y. State Mus. Nat. Hist. (Explana- 

 tion of Plate 13). 

 Syn. Ctenocrinus (in part) — Shumard ; Trans. Acad. Sci. St. Louis, Yol. II., p. 360. 



