130 ECHINODERVrS. 



marginal nodes rather small, distant. Surface smooth. Spines 

 large, attaining a length of 8 or 9 centimeters ; very heavy, and 

 nearly of a uniform size throughout the entire length. A few 

 long spinous projections stud the surface at irregular distances. 

 Horizon and localities. — Upper Carboniferous, Upper 

 Coal Measures: Independence (Jackson county). 



Archaeocidaris biangulata Shumakd. 



r 



Plate XV, flgB. la-c. 

 Arehoeocidaris biangulata Shunaard, 1858: Trans. St. Louis Acad. Sei. 

 vol. I, p. 224. 



Interambulacral plates as in A. agassizi, but somewhat 

 wider than high, and with the boss much larger. Spines mod- 

 erately stout, with a broad alate extension running longitudi- 

 nally on opposite sides from near the crenulated annulation to 

 the end. Both the central thickened portion of the spine and 

 its expansions are covered by small scattered spinous tubercles. 



Horizon and localities. — Upper Carboniferous, Upper Coal 

 Measures : Lexington, Kansas City. 



Archaeocidaris aculeata Shumard. 



Plate XV, flg. 3. 



ArchcBocidaris aceulata ^lavimKrd. , 1S58: Trans. St. Louis Acad. Sci., vol. 



I, p. 223. 

 Archceocidaris verneuiliana Swallow, 1858 : Trans. St. I.ouis Acad. Sci., 



vol. I, p. 180. (Not King, Per. Foss., pi. vi, figs. 22-24.) 

 Archceocidaris gracilis Newberry, 1861 : Rept. Colorado Riv. West, Ives^ 



Exp., p. 117, pi. 1, figs. 4-4a. 



Known only from spines, which are long, slender, with 

 numerous short spinous processes, lower part contracted some- 

 what. 



Horizon a7id localities —JJ piper Carboniferous, Upper 

 Coal Measures : New Point (Jackson county). 



Archaeocidaris dininnil White. 



Archceocidaris dininnii White, 1880* Proc. U. S. National Museum, vol. 



ir, p. 260, pi. i. figs, 13-14. 

 Archceocidaris dininnii White, 1883: U. S. Geog. and Geol. Sur. Terr., 



12th Ann. Rep., p. 131, pi. xxxv, figs. 6a-b. 



