40 Trans. Acad. Sci. of St. Louis. 



has been described as having surface markings like those of 

 the North view specimens, so that there can be little doubt as 

 to the identity of the species. 



EuPHEMUs ? sp. 



PI. v.f. 10-11. 



A single imperfect specimen of this little species has been 

 found in the Northview fauna, about one half of the outer 

 whorl being preserved. It is 8^ mm. in diameter and ex- 

 pands gradually towards the aperture, the greatest thickness 

 of the shell being 5 mm. The shell is umbilicate, the margin 

 of the umbilicus being angular. The outer portion of the 

 shell from the margin of the umbilicus on one side to the 

 margin of the opposite umbilicus is subsemicircular in outline, 

 becoming slightly angular towards the aperture; no dorsal 

 band marking the periphery. The surface is marked by twelve, 

 equal, revolving costae which extend to the margin of the 

 aperture, the spaces between being about equal in width to 

 the costae themselves. The costae apparently increase in 

 number as the shell increases in size, by the addition of new 

 ones, at the margin of the umbilicus. 



It is possible that this species should not be placed in the 

 genus Euphemus because of the presence of the umbilicus, 

 and because the revolving costae extend to the aperture of 

 the shell. It agrees more closely with this genus, however, 

 than with any other, and is therefore provisionally placed 

 in it. 



BucANiA ? sp. 



PL V.f. 12. 



Shell rather abruptly expanding at the aperture, the cross- 

 section regularly curved on the outside, with a narrow, 

 slightly elevated peripheral band. Surface of the shell 

 marked by fine thread-like revolving costae about one mm. 

 apart, with about four very much finer ones in each interme- 

 diate space, and also by fine transverse lines of growth which 

 curve backward very slightly as they approach the peripheral 

 band. Aperture wider than deep with a dorsal notch appar- 

 ently of moderate depth. 



Remarks. Only two specimens of this shell have been 



