REVISION OF PALEOZOIC STELLEROIDEA. 253 



the name of Sturtzaster , with Palseocoma marstoni SaJter as the 

 genotype. 



In 1910 Schondorf was able to study "several right good examples" 

 of S. marstoni, and strangely the form turns out not to be an asterid 

 but an aulurid, with the essential ambulacra! characters of Lap- 

 wortJiura miltoni. He states that the ambulacrals are not alternate, 

 as stated by Salter, but opposite one another. Therefore the 

 ambulacrals and the ad ambulacrals are also opposite. The ad am- 

 bulacrals bear two or three spines on then" outer edges, and Salter's 

 statement and figures showing two columns of ossicles outside of the 

 ambulacrals appear to be very wrong. Schondorf states that the 

 peculiar preservation of the arm skeleton has given rise to this state- 

 ment of Salter, and that there are only ambulacrals and adambula- 

 crals present. The oral skeleton is distinctly adambulacral. A 

 madreporite is not determinable. 



On the dorsal side, all that can be clearly made out is the presence 

 of ambulacrals and adambulacrals, all of which are arranged in trans- 

 verse rows. 



STURTZASTER MARSTONI (Salter). 



Palseocoma marstoni SALTER, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 328, 

 pi. 9, figs. 3a-3c. WRIGHT, Mon. British Foss. Echinod., Oolitic, vol. 2, 

 pt. 1 (Palseontogr. Soc. for 1861), 1862, p. 30, fig. 17. QUENSTEDT, Petrefacten- 

 kunde Deutschlands, vol. 4, 1876, p. 81, pi. 92, fig. 43. 



Sturtzaster marstoni SCHONDORF, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, 

 vol. 63, 1910, p. 217. 



Formation and locality. Common in the Lower Ludlow of Church 

 Hill, Leintwardine, England. Specimens are in many museums, the 

 United States National Museum and the Yale Museum both having 

 individuals. See S. colvini and S. cygnipes. 



Cat. Nos. 60624, 60625, U.S.N.M. 



STtfRTZASTER COLVINI (Salter). 



Palseocoma colvini SALTER, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 328. 

 WRIGHT, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Palseontogr. Soc. 

 for 1861), 1862, p. 30. 



Sturtzaster colvini SCHONDORF, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 

 63, 1910, p. 219. 



Formation and locality. In the Lower Ludlow, Leintwardine, Eng- 

 land. "Probably completely identical with 8. marstoni." (Schondorf.) 



STtJRTZASTER CYGNIPES (Salter). 



Palseocoma cygnipes SALTER, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 329. 

 WRIGHT, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Palaeontogr. Soc. 

 for 1861)', 1862, p. 30. 



Sturtzaster cygniceps (QIC) SCHONDORF, Jahrb. nassauisch. Ver. Naturk., Wies- 

 baden, vol. 63, 1910, p. 219. 



Formation and locality. Lower Ludlow, Leintwardine, England. 

 " Probably completely identical with S. marstoni." (Schondorf.) 



