142 Trans. Acad. Sci. of St. Louis. 



species and by the elongate spire, very short and rather 

 oblique aperture, broad shallow sinus formed upon a double 

 submedian and more or less nodulose peripheral elevation and 

 very short, broadly obtuse paucispiral embryo. The three 

 species represented by material in my cabinet may be distin- 

 guished among themselves as follows : — 



Nodules of the peripheral carinae smaller, not coalescent longitudi- 

 nally; aperture one-third as long as the shell or nearly so 2 



Nodules ol the peripheral carinae coarser, each being fused with its op- 

 posite, forming large longitudinal nodules; spire relatively more 

 elongate, the aperture about a fourth as long as the shell. 3 



2 — Spiral carinules relatively coarser, generally two in number between 



the central double peripheral carina and the lower margin; lower of 

 the two subsutural carinae nodulose; lines of growth very coarse, 

 cancellating the body whorl below the convexity. Length of a 

 specimen of 5 body whorls, 7 mm.; width, 2.6 mm. Upper Claiborne 



ferruginous sand terebriformis Meyer 



Spiral carinules fine; spire whorls shorter and more transverse, the 

 second carinule below the suture simple and not nodulose; but one 

 raised line between the periphery and lower margin and another 

 forming the latter; space between the nodulose peripheral carinae and 

 subsutural carinules much longer, being twice as long as the width of 

 the peripheral band ; lines of growth distinct and uneven but feebler than 

 in terebriformis. Length of a specimen of about 7 body whorls, 10 mm. ; 

 width, 3 mm. Lower Claiborne Eocene of St. Maurice, La. .obtasa n. sp. 



3 — Form very slender; subsutural carinae simple, very coarse and nearly 



contiguous; peripheral carinae coarse, separated from the subsutural by 

 a concave space which is subequal in length to the width of the peri- 

 pheral duplex band and having two fine but strongly elevated and very 

 approximate spiral threads; space below the peripheral nodulose 

 band but little longer than the width of the latter and having 

 one coarse carinule and another forming the lower margin; lines of 

 growth strong and uneven on the' body whorl below the convexity. 

 Length of a specimen of 9 body whorls, 10.6 mm.; width, 2.8 mm. 

 Lower Claiborne Eocene of Moseley's Ferry, Burleson Co., 

 Texas < longispira n. sp. 



In terebriformis the spiral depression below the subsutural 

 carinae is only about as long as the width of the duplex peri- 

 pheral band, while in ohtusa it is fully twice as long as the 

 latter, giving these two species a distinctly different facies. 

 Longispira is widely different, and, besides the characters 

 noted in the table, has a still shorter, more obtuse and 

 scarcely at all reflexed beak, which is sometimes umbilicate 

 along the callus of the inner lip ; it was collected in consid- 



