EEVISION OF PALEOZOIC STELLEKOIDEA. 233 



Uli'ich in the lower Eden at about 100 feet above low-water mark 

 in the Ohio River at Covington, Kentucky. This material is now 

 in the Ulrich collection of the United States National Museum. 

 Other poor specimens from a still lower level in the Eden and asso- 

 ciated with Triarthrus are from the fii'st ward, eastern Cincinnati. 

 Two specimens are at Yale University. 

 Cat. No. 60615, U.S.N.M. 



ALEPIDASTER MIAMIENSIS (Miller). 



Protaster miamicnsis Miller, Journ. Cincinnati Soc. Nat. Hist., vol. 5, 1882, 

 p. 116, pi. 5, figs. 6-66. — J. F. James, Journ. Cincinnati Soc. Nat. Hist., 

 vol. 18, 1896, p. 138.— Parks, Trans. Canadian Inst., vol. 8, 1908, p. 368. 



Original description. — ''This species is large, with a proportion- 

 ally small disk. A specimen havmg a disk four-tenths of an inch 

 in diameter, has rays an inch in length. Five specimens have 

 been examined, all showing the ventral side. The dorsal side is 

 unknown. Oidy that part of the disk between the rays is visible 

 in any of the specimens, and the plates are so anchylosed together 

 that no special definition of them can be given. The rays are long 

 and coarser and stronger than usual in this genus, though they were 

 quite as pliable and llexuous when living as others. Two series of 

 subquadrangular plates, or ambulacral ossicles, alternating with 

 each other, constitute the bottom of each ambulacral furrow; these 

 are bordered by spinous adambulacral plates, which terminate at 

 the angles of the mouth in only five oral plates." 



Formation and locality. — In the Eiclimond formation, about 

 Waynesville, Ohio. The specimens are in the Harris collection 

 of the United States National Museum. 



Cat. No. 40886, U.S.N.M. 



Genus GREGORIURA Chapman. 



Gregoriura Chapman, Proc. Royal Soc. Victoria, n. ser., vol. 19, 1907, p. 24, pi. 6, 

 fig. 1; pi. 8, figs. 1, 3. — ScHONDORF, Jahrb. nassauisch. Ver. Naturk., Wies- 

 baden, vol. 63, 1910, p. 238. 



Original definition. — "A Protasterid in which the usual boot- 

 shaped ambulacrals are laterally developed, and modified into a 

 subtriangular form. Ossicles on each side of the ambulacral canal 

 subalternate, excepting at the junction with the mouth frames, 

 where they are parallel. Adambulacral ossicles narrow, slender, 

 extending laterally in a line with the proximal liordcr of the ambu- 

 lacral ossicle. Spine-bearing plates, slender, at right angles to the 

 ad ambulacrals, carrying (in the genotype) two conspicuous spines. 

 Oral skeleton having jaw plates three-fourths the length of the 

 mouth frames; teeth thick and prominent. No traces of a disk 

 preserved in the specimen on which the genus is founded. Arms 

 very slender and very flexible." 



