HYDROZOIDS AND CORALS. 113 



bede. Insofar as present observation goes, no traces of the 

 spinous processes on the epithecal surface have yet been noted ; 

 and this difference seems to readily distinguish this form from 

 Z, dalei and Z. spinulosa, with which it is usually associated 

 and liable to be confounded. 



Zaphrentis illinoisensis Worthen. 

 Zaphrentis ilUaoisensis WoTthea, 1890: Geol. Sur. Illinois, vol. VIII, p. 

 77, pi. ix, figs. 4-4a. 



Corallum large, rather short, but slightly curved; rapidly 

 expanding to the calycinal margin, where it is very broad. 

 Epithecal folds transverse, unusually wide, prominent. Lamel- 

 lae large, widely separated and seldom exceeding 40 in number. 



Horizon and localities, — Lower Carboniferous, Keokuk 

 limestone: Wayland ( Clark county) ; Warsaw (Illinois ) ; Keo- 

 kuk and Bonaparte ( Iowa). 



Zaphrentis dalei Edwards & Haime. 



Plate xiii, fig. 12. 

 Zophrentis dalei Edwards & Haime, 1851: Monog. d. Polyp. Foss. d. 



Ter. Pal,, p. 329. 

 ZaphrentU dalei Worthen, 1890: Geol. Sur. Illinois, vol. VIII, p. 71, pi. 



X, figs. 12-12a. 



Corallum simple, large, elongate-conical, more or less 

 curved. Calyx somewhat oblique, subcircular, deep ; septal 

 fossette well defined and located on the side of least curvature. 

 Lamellae forty to sixty or more in number, rather prominent, 

 thin, somewhat irregular and usually more or less bent toward 

 the center. External surface rugose and covered by short, 

 widely scattered spines. 



Horizon and localities. — Lower Carboniferous, Keokuk 

 limestone and shales : St. Francisville, Boonville, Canton ; 

 Burlington limestone : Hannibal, Louisiana, Springfield. 



From Warsaw Worthen has described three other species 

 of Zaphrentis : Z. illinoisensis, Z. spergenensis and Z. varsavien- 

 siSf whose affinities are not as yet fully understood. They also 

 occur at various places in Missouri, along with numerous other 

 forms apparently undescribed. The original specimens of 

 Edwards & Haime also came from Warsaw, just across the 



