307 



Family RAPHISTOMIDAE 



Genus RAPHISTOMA Hall 

 EAPHISTOMA ? OBTUSUM Cleland 



Plate XXXI, Figs. 15-17 



Raphistoma obtusa Cleland, 1900, Bull. Amer. Pal., vol. iii, p. 125 (253), 

 pi. xv, figs. 7-9. 



Description. Shell averaging 10 mm. in width, convex above, much 

 compressed and consisting of three volutions, forming an apical angle 

 of 130. Umbilicus about one-third the shell diameter, with angular 

 margins. Upper surface of volutions compressed, outer edge acute, and 

 inner edge rounded. 



The compressed form, angular margin, and few volutions of this shell 

 will distinguish it from associated species. 



Occurrence. BEEKMANTOWN LIMESTONE (Stonehenge member). 

 Several localities around Hagerstown and Funkstown, Maryland. Tribes 

 Hill limestone of New York. 



Collection. U. S. National Museum. 



EAPHISTOMA ? COLUMBIANUM Weller 



Plate XXXI, Figs. 22, 23 



Raphistoma columbiana Weller, 1903, Geol. Surv. New Jersey, Pal., vol. iii, 

 p. 128, pi. iv, figs. 3-5. 



Description. Shell nearly smooth, consisting of about three and one- 

 half volutions, flat above and rounded below, which form a slightly 

 elevated spire and have a small umbilicus below. Outer edge of shell 

 sharply rounded and slightly elevated above. The outer volution has a 

 broad, ill-defined sulcus just below and paralleling the periphery. The 

 type specimen measures 13 mm. in diameter and 6.5 mm. in height. 



Occurrence. BEEKMANTOWN LIMESTONE (Stonehenge member). 

 Hagerstown, Maryland. The types are from the Kittatinny limestone 

 of New Jersey. 



Collection. U. S. National Museum. 



