220 



ECHINODERMATA ECHINOIDEA 



SUB-BRANCH III 



Koninckocidaris, Dollo and Buiss. Europe. Perischodomus, M'Coy. Car- 

 boniferous ; Europe and North America. 



Archaeocidaris, M'Coy (Palaeocidaris, Desor), (Fig. 352). Test large. Amb 

 straight, reaching to the stoma ; plates irregular, imbricating adorally. I Amb 



FIG. 351. 



A, Lepiiloreittnix llhenamis, Beyr. Devonian ; Wipperfiirtli, Eifel. Cast of the interior of test showing jaws, 

 l/i (after J. Muller). B-D, Lepidocentrus Mullen, Schultze. Devonian ; Gerolstein, Eifel. J3, Portion of Amb, 

 enlarged. C, Several lAmb plates, 1/1- A Two detached I Amb plates, showing oblique edges, i/j. 



with three to seven columns of large thin plates, the median ones hexagonal, the 

 adambulacral pentagonal or rounded. Median plates bevelled slightly over 

 those on either side, and these over others to the ambulacral edge. Each lAinb 



FIG. 352. 



Archaeocidaris Wortheni, Hall. Sub-Carboniferous ; Burlington, Iowa. A, Portion of ventral region, showing 

 jaws, Vi- -B, An I Amb plate viewed from above and from the side. C, Portion of Amb, enlarged. D, Spine, J /i 

 (after Hall). 



plate with a large primary tubercle, surrounded by a large flat scrobicule and 

 a circlet of granules. Primary spines large, usually serrated. Carboniferous 

 Limestone ; Great Britain and North America. Permian England. 



Lepidocidaris, Meek and Worthen. Sub-Carboniferous ; North America. 

 Lepidechinus, Hall. Upper Devonian and Sub-Carboniferous ; North America. 



Xenocidaris, Schultze. Founded upon clavate spines from the Devonian of 

 the Eifel. 



