200 Systematic Paleontology 



Genus ZAPHRENTIS Rafinesque 



Zaphrentis rcemeri Milne-Edwards and Haime 



Plate XVIII, Figs. 3-7 



Zaphrentis rwmeri Milne-Edwards and Haime, 1851, Polypiers Fossiles des 



Terr. Pal., p. 341. 

 Zaphrentis rwmeri Hall, 1883, Rept. State Geol. N. Y. for 1882, pi. i, figs. 1-21. 

 Zaphrentis rwmeri Hall, 1887, Pal. N. Y., vol. vi, p. 2, pi. i, figs. 11, 12. 

 Zaphrentis rcemeri ? Waller, 1903, Pal. N. J., vol. iii, p. 270. 



Description. — Corallite simple, conical, curved near apex, gradually 

 enlarging from apex to calyx. Annulated by strong constrictions between 

 which are fine transverse stride ; very distinctly striated longitudinally by 

 furrows marking extremities of septa. Increasing by calicular gemma- 

 tion, a smaller calyx arising from the center, or side, of the old in such a 

 manner as to produce projecting sharp-edged annulations formed by the 

 edges of old calyx. 



Theca formed by the fusion of ends of septa. Calyx often very irregular 

 in shape due to method of reproduction, deep, its sides erect or spreading. 

 Septa alternately long and short, usually not extending fully to center, 

 irregularly spaced and variously bent, about 60 to 65 in individual, 22 to 

 25 mm. in diameter. Fossula not very distinct. In cross-section primary 

 septa vary in length, usually falling short of center, secondary septa much 

 shorter, their length variable. Septa irregularly curved. Tabulte numer- 

 OU.S, close. In many individuals the tahuke appear few and distant, prob- 

 ably due to poor preservation, although it may be varietal. 



Length, 45 mm.; diameter of calyx, 20 mm. 



The exact stratigraphic position of the Maryland Helderberg material 

 is not assured. 



Occurrence. — Helderberg Formatio.v. Cumberland; Devil's Back- 

 bone; Knobly Mountain 6 miles south of Cumberland; Martin Mountain. 

 Oriskany Formation, Eidgely Member. Near Cumberland. 



Collections. — Maryland Geological Survey, U. S. National Museum. 



