Klem — Revision of the Palaeozoic Palae'echinoidea. 67 



b. EociDARis Desor 1858.* 

 Like Archaeocidaris only the primary tubercle has no halo. 



1. EociDARis BLAiRi Miller. 



1891. Eocidaris hlairi. Miller, Adv. Sheets 17th Rep. 

 Geol. Surv. Ind., p. 73, pi. 12, figs. 1, 2. 



1892. Eocidaris blairi. Miller, 17th Rep. Geol. Surv. Ind., 

 p. 683, pi. 12, figs. 1, 2. 



Central tubercle large and perforated. Space between the 

 central tubercle and the marginal tubercles concave. 



Primary spines long, tapering gradually, compressed 

 slightly. Articulating end somewhat enlarged. Surface of 

 the spines finely granular. Secondary spines very small. 



Geological formation and locality: Keokuk Group, Boon- 

 ville, Mo. 



2. Eocidaris forbesianus De Koninck. 



1863. Cidaris Forhesiana. De Koninck, Quart. Journ. 



Geol. Soc. Lond., vol. 19, p. 4, pi. 4, figs. 1, 2. 

 1863. Cidaris forhesiana. De Koninck, Foss. Pal. de 



rinde, p. 22, pi. 3, figs. 1, 2. 

 1885. Eocidaris forhesiana. Waagen, Mem. Geol. Surv. 

 India, ser. 13, vol. 1, p. 819, pi. 95, fig. 5-16. 



Primary tubercle large with a high neck and a deeply 

 crenulated collar. Scrobicule large and smooth, surrounded 

 by a narrow margin of rather large distant secondary tuber- 

 cles. 



Primary spines rather flat on one side, tapering distinctly 

 toward the articulating end. Head thick with a very promi- 

 nent ring, which is crenulated. 



Geological formation and locality : Productus Limestone, 

 Kalta, Golawali, Chidru and in the Bazarwan, India. 



Synopsis des ;£]cbimdes Fossiles, p. 155. 



