114 HYDEOZOIDS AND CORALS. 



river from Alexandria, Clark county. The form seems to be 

 widely distributed in the Keokuk rocks of the Mississippi 

 basin, and probably occurs also in the Burlington beds. 



Zaphrentis spinulosa Edwaeds & Haime. 



Zaphrentis spinulosa'ECiw&Tds tSz Haime, 1851: Monog. d. Polyp. Foss. d. 



Ter. Pal., p. 334. 

 Zaphrentis spinulifera Hall, 1S5S: Geol. lowa, vol. I, p. 650, pi. xxii, 



figs. la-b. 

 Zaphrentis spinulosa Worthen, 1S90: Geol. Sur. Illinois, vol. VIII, p 73, 



pi. X, figs. 6-6a. 

 Zaphrentis peLlaensis Worthen, 1890: Geol. Sur. Illiroie, vol. VIII, p. 74, 



pi. ix, figs. 6-6a ; and pi. x, figs. 11-lla. 



Very similar to Z. dalei Ed. & H., but much smaller, more 

 robust and highly spinous. 



Horizon and localities. — Lower Carboniferous, Keokuk 

 limestone: CurrjYJlle, St. Francisville, Boonville, Keokuk 

 (Iowa); Saint Louis limestone : Clark and Saint Louis coun- 

 ties, and in Iowa at Fort Dodge, Pella, Fairfield, Mt. Pleasant 

 and elsewhere; Kaskaskia limestone : Ste. G-enevieve. 



Zaphrentis spinulosa is very much like immature indi- 

 viduals of Z dalei, but the much greater abundance of the 

 epithecal spines, the usually much broader calycinal disk, seem 

 sufficient to distinguish it from that species. The form appears 

 most characteristic of the Saint Louis limestone, in which it is 

 widely distributed geographically. It also occurs abundantly 

 in the upper portion of the Keokuk limestone, and is found 

 sparingly in the Kaskaskia. Hall's form, Z. spinulifera, origin- 

 ally described from Warsaw, Illinois, is without doubt identi- 

 cal with the species under consideration, and is so regarded 

 here. 



Zaphrentis varsavenis Worthen. 



Zaphrentis varsavensis Worthen, 1890: Geol. Sur. Illinois, vol. VIII, p. 78, 

 pi, X, figs. 0-9a. 



A small, symmetrical, moderately curved form, with 20 to 

 32 lamella. 



Horizon and localities. — Lower Carboniferous, Keokuk 

 Jmestone : LaCrange, Warsaw (Illinois). 



