CRINOIDS. 189 



Oalyx like A. verrucosus but smaller, with lower ventral 

 side, aud very different ornamentation. 



Horizon and localities. — Lower Carboniferous, Upper 

 Burlington limestone : Ash Grove (Greene county); Quincy 

 (Illinois); Burlington ( Iowa). 



Actinocrinus verrucosus Hall, 



Plate xxlv, /ig. 3. 



Actinocrinus verrucosus Hall, 1858: Geol. Iowa, vol. I, p. 578, pi. X, figs. 



7a-b. 

 Actinocrinus asterias McChesney, 1860: New False. Foss., p. 9. 

 Actinocrinus asterias McChesnej , 1867: Trans. Chicago. Acad. Sci., vol. 



I, p. 9, pi. V, fig. 6. 

 Actinocrinus verrucosus Meek & Worthen, 1873: Geol. Sur. Illinois, vol. V, 



p. 341. 



Calyx somewhat urn-shaped, strongly lobed at the arm 

 bases. Basal disk large, with thickened border, which is deeply 

 emarginate at the sutures. Radials large, about as high as 

 wide. Ventral side elevated, composed of large nodose plates ; 

 ventral tube long and stout. Surface of plates greatly arched 

 or nodose; often with slight indications of rounded ridges 

 passing from one plate to another. 



Horizon and localities. — Lower Carboniferous, Upper Bur- 

 lington limestone : Hannibal, Ash Grove (Greene county), Ste. 

 Genevieve, and in Howard county. 



Actinocrinus glans Hall. 



Plate xxiv, figs. 2a-b. 



Actinocrinus glans Hall, 1860: Geology Iowa, vol. I, Supp., p. 16. 

 Actinocrinus eryx Hall, 1861 : Desc. New Palae Crinoids, p. 12. 

 Actinocrinus hlairi MXWer , \8^i: Geol. Sur Indiana. 18th Ann. Rep , adv. 

 sheets, p. 35, pi. v, figs. 27-29. 



Calyx large, elongate-turbinate, ventral side but slightly 

 convex, arm-openings directed upward ; calyx plates smooth, 

 slightly convex. 



Horizon and localities. — Lower Carboniferous, Upper Bur- 

 lington limestone : Ash Grove. 



Actinocrinus lowei Hall. 



Actinocrinus lowei Hall, 1858: Geology Iowa, vol. I, p. 611, pi. xv, figs. 

 5a-b. 



