REVISION OF PALEOZOIC STELLEROIDEA. 263 



Genus EOSPONDYLUS Gregory. 



Ophiurella STURTZ (not Agassiz, 1834), Palseontographica, vol. 32, 1886, p. 77. 

 Eospondylus GREGORY, Proc. Zool. Soc. London for 1896, 1897, p. 1039. 



Original diagnosis. "Disk circular. Ambulacral ossicles com- 

 pletely fused into vertebral ossicles, each of which, however, is trav- 

 ersed by a pore. The adambulacral ossicles are somewhat pear- 

 shaped. The podial pores are at the posterior angles of the ventral 

 arm plates." 



Genoholotype and only species. Ophiurella primigenia Stiirtz. 



EOSPONDYLUS PRIMIGENIUS (Stiirtz). 



Ophiurella primigenia STURTZ, Palseontographica, vol. 32, 1886, p. 77, pi. 8, 



figs. 1, 2; vol. 36, 1890, p. 210, pi. 26, figs. 6, 7. 

 Eospondylus pnmigenia GREGORY, Proc. Zool. Soc. London for 1896, 1897, 



p. 1039. 



Formation and locality. Lower Devonic, Bundenbach, Germany. 



Genus MIOSPONDYLUS Gregory. 



Ophiura rJienana STURTZ, Verb, naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, 



p. 29, pi. 1, figs. 1-3. 

 Miospondylus rhenanus GREGORY, Proc. Zool. Soc. London for 1896, 1897, p. 



1039. SOLLAS and SOLLAS, Philos. Trans. Koy. Soc. London, ser. B, vol. 



202, 1912, p. 226. 



Onginal diagnosis (Gregory). "Disk circular. Ambulacral ossi- 

 cles completely united; each half of the vertebral ossicle is boot- 

 shaped. The oral angles each consist of a pair of syngnaths without 

 jaw plate. The ventral arm plates are small and are not notched 

 by podial pores." 



Genoholotype and only species. Opliiura rhenana Stiirtz (citations 

 as above). Lower Devonic, Bundenbach, Germany. 



Remarks. Eospondylus and Miospondylus " agree in family char- 

 acters with Eoluidia, but differ from it in the structure of both the 

 ambulacral and adambulacral plates." (Gregory.) 



Family AGANASTERID.^ Stiirtz. 



Aganasteridse STURTZ, Verb, naturh. Ver. preuss. Rheinl., etc., vol. 56, 1900, 

 p. 203. SCHONDORP, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 

 1910, p. 235. 



Genus AGANASTER Miller and Gurley. 



Aganaster MILLER and GURLEY, Sixteenth Rep. Geol. Surv. Indiana, 1891, p. 

 372; authors' extracts, 1890, p. 57. GREGORY, Proc. Zool. Soc. London for 

 1896, 1897, p. 1039. 



^ Ophiopege BOHM, Zeit. geol. Gesell., vol. 45, 1893, p. 159 (same genoholotype as 

 for Aganaster). 



Original description. "In 1869 Meek and Worthen described an 

 Ophiuroidea, in the Proceedings of the Academy of Science of 



