Kleni — Revision of the Palaeozoic PaJaeechinoidea. 23 



1873. Fholidocidaris irregularity . Meek and Worthen, Geol. 

 Surv. 111., vol. 5, p. 512, pi. 15, fig. 9. 



1874. Pholidocidaris irregularis. Meek, Amer. Journ. Sci., 

 ser. 3, vol. 7, p. 375. 



1874. Pholidocidaris irregularis. Lovc'n, Kongl. Svens. 



Vetens. Akad. Handl., Bd. 11, no. 7. p. 40. 



1889. Pholidocidaris irregularis. Miller, N. Amer. Geol. 

 Pal., p. 269. 



1895. PJiolidocidaris irregularis. Keyes, Proc. Iowa Acad. 

 Sci., vol. 2, p. 180. 



1896. Pholidocidaris meeki. Jackson, Bull. Geol. Soc. 

 Amer., vol. 7, p. 210, pi. 9, fig. 54. 



Interambulacral plates thin and sharp at the edges. Pri- 

 mary tubercle present on lower (?) part only and on the 

 marginal plates, in the upper (?) part. Ambulacral plates 

 very irregular, six or more columns. Pores in pits in the 

 center of each plate, surrounded by a circular depression. 

 Primary spines taper gradually, are rounded, nearly straight, 

 and marked with minute, crowded lono;itudinal striae. 



Geological formation and locality : Keokuk and Hamilton 

 Groups, near Nauvoo and Warsaw, 111. 



INSUFFICIENTLY DETERMINED SPECIES. 



1, Pholidocidaris gaudryi Julien. 



1874. Lepidocentrus Milnsterianus. Julien, Compt. Rend. 

 Acad. Sci. Paris, T. 78, p. 76. 



1890. Melonites Gaudryi. Julien, Compt. Rend. Acad. Sci. 

 Paris, T. 110, p. 737. 



1896. Pholidocidaris Gaudryi. elulien, Terr. Garb. Marin 

 de la France Centrale, p. 131, pi. 6, figs. 1, 2, 6, 7. 



Geological formation and locahtv : Carboniferous, I'Ar- 

 doisiere. 



2. Pholidocidaris tenuis Tornquist. 



1897. PJiolidocidaris tenuis. Tornquist, Ablidl. Geol. 

 Karte Elsass-Lothr., Bd. 5, Hft. 6, p. 767, taf. 21, 

 figs. 8, 9; taf. 22, fig. 8. 



