228 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. 



PROTASTER (?) STELLIFER Ringueberg. 



Protaster stellifer Ringueberg, Bull. Buffalo Soc. Nat. Sci., vol. 5, 1886, p. 7, pi. 1, 

 fig- 2. 



Generic relations not established. 



Original description. — "Disk of medium size, flat, circular, sMghtly 

 flexible, distinct from the rays on the dorsal side, and has on that 

 side a quinque-dentate, stellate, central elevation, which again has 

 a central, stellate depression of about one-haK the lateral extension 

 of the stellate elevation upon which it is impressed. The points of 

 the star-like figure are opposite the several rays and extend about 

 two-thirds across the disk. 



''Surface finely granulose. Rays slender, almost imperceptibly 

 tapering in the upper haK of their known length; rounding on the 

 dorsal side, with two rows of regular, quadrilateral, alternating 

 [ambulacrall plates which can with difficulty be made out, and which 

 have a fine granulose [integumentary] surface resembUng the surface 

 of the disk; opposite each transverse suture there is a corresponding 

 linear depression across the surface of the opposite plate on the other 

 side of the median suture, wliich at first sight gives the impression 

 that the ray is composed of opposite plates of only one-half the real 

 length. 



"Ventral side with ten short, oral plates which are slightly sepa- 

 rated below, and meet at the discal surface, where they are rounded. 



"Ambulacral series long, regularly quadrilateral; alternately 

 arranged. 



"Adambulacrals indistinct in the only specimens found showing 

 the ventral surface. 



"Marginal series sUghtly imbricating; spiniferous; spines rather 

 short." 



Formation and locality. — Three specimens were collected in the 

 Rochester shale of the Siluric at Lockport, New York. They are in 

 the author's collection. Two other fine specimens were found by C. 

 J. Sarle at Lockport and are now at Yale University. Another good 

 specimen is in the Walker collection of the University of Toronto 

 (No. 1007) ; it was found at Grimsby, Ontario. 



Genus ALEPIDASTER Meek. 



Plate 36, fig. 4; text fig. 26. 



Alepidaster Meek, Amer. Journ. Sci., ser. 3, vol. 4, 1872, p. 275; Geol. Surv. Ohio, 



Pal., vol. 1, 1873, p. 68, at end of specific description. 



Protasterina Ulrich, Journ. Cincinnati Soc. Nat. Hist., vol. 1, 1878, p. 95. — J. F. 



James, Joiu-n. Cincinnati Soc. Nat. Hist., vol. 18, 1896, p. 139 (genoholotype, 



P. fimbriata Ulrich). 



Original description. — "The only specimen I have seen that is 



certainly known to belong to this species [P. f granuliferus] is very 



