142 Carl 0. Dunbar J 



ately narrow, its lines of growth are concave forward, and its 

 lower margin is at the periphery. In the new genus, the band is 

 convex, broad, its lines of growth arch forward, and it is located 

 above the periphery of the whorl. 



The genus is erected to receive the new species 5". tcnnesseen- 

 sis, which is the genotype. 



Etymology: The genus is named in honor of Tennessee's 

 great geologist. Professor James Safford. 



Saffordella tennesseensis, n. sp. 



Plate IV, fig. 17 

 Description: Shell depressed subconical, consisting of about 

 three and a half rapidly enlarging whorls. Apical angle about 

 90°. Base ventricose and practically imperforate. The last 

 whorl much larger than all the preceding ones. In the two 

 earliest volutions the whorls are well rounded and the sutures 

 rather deep, but with growth the later whorls become more quad- 

 rangular in section, the lower and upper slopes becoming flat- 

 tened and the periphery bluntly rounded angular. The suture 

 at the same time becomes shallower. The aperture is subquad- 

 rate, as deep as wide, broadly and deeply notched at the periphery, 

 and also marked by a rounded sinus next to the columella. The 

 slit-band is 4.5 mm. wide and located on the upper slope of the 

 whorl, its lower margin being about i mm. above the ambitus. 

 The band is clearly delimited by shallow depressed margins. It 

 is gently convex and its growth-lines arch forward to an extent 

 about half as great as the width of the band, indicating that its 

 aperttiral margin must have been a short rotmded crest either at 

 the base of the notch or within the slit, if indeed the shell pos- 

 sessed a slit. Surface of the shell marked only by fine lines of 

 growth. On the upper slope, these lines, taking a sigmoidal 

 course, bend strongly backward to the band, while on the under 

 slope they first run strongly forward, then curve backward in 

 crossing the ventricose center of the base, and finally forward 

 again as they reach the inner lip. 



Dimensions : Height, 40 mm. ; width, 39 mm. ; height of aper- 

 ture, 24 mm. ; width of same, 24 mm. 



Occurrence: A single specimen was found in the Rockhouse 

 shale at Rockhouse on Horse Creek, Hardin County. 



