MARYLAND GEOLOGICAL SURVEY 313 



Family SINUITIDAE 



Genus SIMJITES Koken 



SlNUITES CANCELLATUS (Hall) 



Plate LV, Pigs. 12-21; Plate L, Figs. 37-39 



Bellerophon bilobatus Emmons (not Sowerby), 1842, Geol. New York, vol. ii, 



p. 392, fig. 6. 

 Bellerophon cancellatus Hall, 1847, Pal. New York, vol. i, p. 307, pi. Ixxxiii, 



figs. lOa-c. 

 ProtowartMa cancellata Ulrich and Scofield, 1897, Minnesota Geol. Survey, 



Pal., vol. iii, pt. 2, p. 872, pi. Ixiii, figs. 1-14. 

 ProtowartMa cancellata Weller, 1903, Geol. Surv. New Jersey, Pal., vol. iii, 



p. 175, pi. xii, figs. 3-5. 



Description. " Shell of medium size, subglobose, close coiled, with no 

 umbilicus when the shell is preserved, but with a small one in the casts. 

 In immature specimens the dorsum of the outer volution is rather sharply 

 rounded, but with increasing age it becomes more broadly rounded, losing 

 entirely the obscure carination of the youngei shells. Sinus shallow, 

 rounded ; the lateral margins of the aperture on either side of the sinus 

 regularly and rather gently convex. Aperture wider than high, subsemi- 

 circular in outline. On the larger internal casts one or more rather broad 

 and shallow, rounded, transverse, wrinkle-like depressions are frequently 

 present near the aperture and parallel with the apertural margin. 



" The dimensions of a large specimen are : Maximum diameter, 21 mm. ; 

 width of aperture, 18 mm." Weller, 1903. 



A wide-spread species of the United States and Canada ranging from 

 the Trenton to and through the Kichmond. In Pennsylvania and Mary- 

 land the species occurs at practically all the outcrops of the fossiliferous 

 Sinuites bed and Eden divisions of the Martinsburg shale. 



Occurrence. MARTINSBURG SHALE. The slopes of Eickard Mountain 

 in Maryland have furnished casts of the species. 



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



