HYDROZOIDS AND CORALS. HI 



Zaphrentis tenella Miller. 

 Plate xiii, lig. 10. 

 Zaphrentis tenella Miller, 1891 : Geol. Sur. Indiana, 17tli Ann. Kept., adv. 

 pheets, p. 11, pi. i, tigs. 17, 18. 



A small, rather slender form, slightly curved and somewhat 

 twisted, with the calycinal margin very oblique to the axis of 

 the corallum. Lamellne about 24 in number. 



Horizon and localities. — Lower Carboniferous, Kinderhook 

 limestone : Sedalia, Louisiana. 



Zaphrentis tantilla Miller. 



Zaphrentis tantilla Miller, 1891 : Geol. Sur. Indiana, 17th Ann. Kept , adv. 

 sheets, p. 11, pi i, tigs. 23, 24. 



Corallum small, very slender, but slightly curved, with 

 20 to 32 lamellse. 



Horizon and localities.— hovfer Carboniferous, Kinderhook 

 limestone : Sedalia ; Burlington limestone : Louisiana, Han- 

 nibal. 



Zaphrentis cylindracea Worthen. 



Plate xiii, flg. 5. 



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



pi. ix, Q.gi. 5, 5a. 



Corallum long, slender, cylindrical, very slightly curved. 

 Calyx moderately deep ; septal fossette not prominent. Lam- 

 ellae 32 to 40 in number. Epithecal surface not wrinkled. 



Horizon and localities. — Lower Carboniferous, Kaskaskia 

 limestone: Ste. Genevieve; Chester (Illinois). 



Zaphrentis elliptica White. 



Plate xiii, figs. 6a-b. 



Zaphrentis elliptica White, 1862: Proc. Boston yoc. Nat. Hist., vol. IX, 



p. 31. 

 Zaphrentis elliptica White, 1833: U. S. Geog. and Geol. Sur. Ter., 12th 



Ann. Rept., p 155, pi. xxxix, figs. 4a-b. 

 Zaphrentis carinata Worthen, 1890 : Geol. Sur. Illinois, vol. VIII, p. 75, 



pi. X, iigs. 3-3a. 



Corallum rather below medium size, robust, slightly curved, 

 somewhat compressed below the middle. Calyx rather deep, 



