REPORT OF THE STATE PALEONTOLOGIST I903 289 



suture) is sharp; the second and third are more raised, prominent, 

 blunt, and each about one fourth as wide as the interspace; the 

 fourth is a Httle nearer the third, less prominent and narrower ; the 

 fifth is nearer the fourth by about half the distance between fourth 

 and third and is about half as wide as the fourth. 



Following the outline of a vertical section through the body 

 whorl, the shell is seen to be slightly angulated ; from suture to 

 outer edge of first costa the line is straight and at right angles to 

 the axis ; a straight line taken from first to third costa would make 

 an angle of about 23° with the axis; the projection of the second 

 costa beyond this line gives a slight convexity to this spiral belt of 

 the whorl ; the outer edges of the third, fourth and fifth costae are 

 more nearly in line with each other and this line is nearly parallel 

 with the axis of the shell, its inclination toward the base being but 

 slight; from the fifth rib the surface approaches the axis by another 

 flattened belt, at an angle of about 45° ; the final approach to the 

 axis is lost. The intercostal spaces are concave, the amount of 

 concavity increasing markedly as the lower costa is approached, 

 giving a rather horizontal surface to the upper portions of the 

 stronger costae or in certain lights making this upper edge appear 

 slightly reflexed. The suture lies at the base of the nearly vertical, 

 spiral belt or just under the fourth costa and is thus situated at the 

 apex of a clearly cut right angle, two sides of which are formed 

 by the flattened belts already described. The shell is faintly marked 

 with transverse striae the more prominent of which are about 2mm 

 apart; between these a still fainter line can in many places be dis- 

 tinguished; their direction is at first very nearly perpendicular to 

 the suture and on the body whorl they appear to run gently back- 

 ward from the fourth costa; they are more easily seen above the 

 suture and here seem to be nearly vertical across and beyond the 

 fourth costa ; finer growth lines may be detected. 



A little more than the first whorl of this specimen is somewhat 

 Natica-like, not angulated, destitute of costae, and the apical angle 

 is more obtuse being about 90°. The transverse striae seem to 

 appear first and are present on the second whorl. The vertical and 

 horizontal flattened belts are present on the third whorl and the first. 



