FOSSILS OF THE VVAVERLY GROUP. 261 



periphery, although flattened on the top of the volution. The individual 

 figured is someAvhat smaller than the specimen used and figured by Dr. C. 

 A. White in Lieutenant Wheeler's Report above cited, but possesses all the 

 characters of those specimens. 



Formation and locality. — In limestones near the base of the Wahsatch 

 limestone, of the age of the Waverly group of Ohio, at Dry Canon, Oquirrh 

 Mountains, and Logan Cafion, Wahsatch Range, Utah. Collected by S. 

 F, Emmons and J. E. Clayton. 



EuoMPHALiTS (Strap AEOLLUS) Ophirensis n. sp. 



Plate IV, figs. 26-27. 



Shell of medium size, broadly conical or subtrochiform ; height equal 

 to two-thirds the greatest transverse diameter of the base; composed of 

 four and a half to five volutions, which are closely coiled, so as to rest nearly 

 upon the surface of the succeeding ones; four of the volutions obliquely 

 compressed on the outer upper portion, and sharply rounded on the periphery 

 and below, giving a somewhat convex trochiform. aspect to the coils. 

 Umbilicus broad and deep, exposing more than one-half of each of the 

 preceding whorls, which are strongly rounded and full. Transverse section 

 of the volution obliquely and irregularly ovate, narrow, and somewhat 

 pointed at the upper end at the junction of the volutions, rounded on the 

 inner, and obliquely flattened or depressed-convex on the outer surface. 



Surface of the shell marked only by very fine transverse lines of 

 growth, which have a slightly backward curvature as they cross the volu- 

 tion. 



This species has something of the form and general appearance of -S'. 

 umbilicus M. & W., from the Coal-Measures (see Geol. Rept. Ills., vol. ii, pi. 

 27, fig. 1), but is more depressed and proportionally broader, without the 

 horizontal flattening on the upper surface of the volutions, which are instead 

 obliquely compressed nearly in the direction of the slope of the spire. 



Formation and locality. — In limestones of the age of the Waverly group, 

 at Dry Canon, Oquirrh Mountains, Utah. Collected by J. E. Clayton. 



